The Ultimate Chocolate Hazelnut Cake with Creamy Nutella Buttercream

For every Nutella enthusiast and chocolate lover, this chocolate hazelnut cake is an absolute dream come true! Imagine sinking your teeth into a remarkably moist chocolate cake, each bite bursting with a luscious chocolate hazelnut spread and finely ground, roasted hazelnuts. To elevate this experience further, the entire masterpiece is enveloped in a velvety, creamy Nutella buttercream. This isn’t just any layer cake; it’s a profound declaration of rich chocolate intensity and the warm, earthy notes of perfectly roasted hazelnuts, promising an unforgettable dessert experience. Whether it’s a special occasion or simply a craving for something extraordinary, this cake delivers pure indulgence.

The culinary pairing of chocolate and hazelnut is truly a match made in heaven, which explains the widespread adoration for Nutella desserts. This classic chocolate cake recipe, perfected over countless trials, offers the ideal balance of flavor and texture, making it an excellent foundation for a majestic layer cake. Its robust structure and delectable taste are so reliable that we proudly feature this very base in other beloved creations, such as our chocolate cake with cream cheese frosting and our opulent triple chocolate cake. This consistency ensures that every chocolate hazelnut cake you bake will be nothing short of spectacular.

Why This Chocolate Hazelnut Cake Will Be Your New Favorite

Get ready to discover why this chocolate hazelnut cake isn’t just a recipe, but a delightful experience waiting to unfold in your kitchen. From its remarkable versatility to its unforgettable flavor profile and exquisite texture, there are countless reasons why this decadent dessert will quickly become a cherished favorite.

A Cake for Every Occasion (and Easy to Prepare!)

This chocolate hazelnut cake is wonderfully versatile, making it the perfect centerpiece for virtually any celebration. Whether you’re planning a festive birthday party, a cozy Christmas gathering, an elegant baby shower, or a charming bridal shower, this cake fits right in. It’s also the ultimate heartfelt gift for the dedicated chocolate lover in your life. What makes this recipe even more appealing is its simplified approach to a layer cake. By utilizing whole cake rounds, we streamline the assembly process without ever compromising on the rich, complex flavors. Plus, for those who love to plan ahead, this cake is an absolute winner. It maintains its incredible moistness beautifully even during storage, allowing you to bake it in advance and enjoy a stress-free celebration.

Unforgettable Chocolate Hazelnut Flavor

Prepare for an explosion of classic flavors that truly make this an epic Nutella cake. We’ve gone all-in on the glorious chocolate and hazelnut combination. The interior boasts a generous layer of chocolate hazelnut spread, generously mixed with chopped roasted hazelnuts, adding both depth and a delightful crunch. But the magic doesn’t stop there! The entire cake is then enrobed in a silky, rich chocolate hazelnut buttercream, also made with Nutella. This multi-layered approach ensures that every single forkful delivers that irresistible, dreamy blend of deep chocolate and earthy, toasted hazelnut notes.

Perfect Harmony of Textures

Texture is paramount in creating a truly exceptional cake, and this recipe delivers on all fronts. The rich chocolate cake layers themselves are incredibly soft and tender, melting in your mouth with every bite. Complementing this is the luxuriously creamy Nutella buttercream, which provides a smooth, decadent coating. To introduce an exciting contrast, we fold bits of chopped roasted hazelnuts into the filling, adding a subtle yet satisfying crunch that elevates the entire sensory experience. This symphony of soft, creamy, and crunchy elements ensures a perfect texture in every slice.

Essential Ingredients for Your Chocolate Hazelnut Cake

Crafting this magnificent chocolate hazelnut cake requires a selection of high-quality ingredients, each playing a crucial role in achieving its signature flavor and texture. Here’s a detailed look at what you’ll need and why it matters.

• Dutch-Processed Cocoa Powder: This special variety of cocoa powder is alkalized, which gives the cake a deeper, darker, and more appealing color. More importantly, it yields a slightly milder and less acidic chocolate flavor, ensuring a perfectly balanced taste that isn’t overwhelmingly bitter. While it might sound like a subtle difference, I assure you, with the intricate layers of chocolate and hazelnut in this recipe, Dutch-processed cocoa powder provides the best foundation for a truly harmonious flavor profile.
• Neutral Oil: Using a neutral-flavored oil like vegetable, canola, or grapeseed oil is key for a moist and tender cake. These oils contribute fat without imparting any strong flavors, allowing the rich chocolate and hazelnut to shine. It also helps to keep the cake moist for longer periods, a definite plus for make-ahead baking.
• Dairy Products: Our recipe incorporates a trio of full-fat dairy products: sour cream, whole milk, and heavy whipping cream. Each plays a vital role. The sour cream and milk, used at room temperature, contribute to the cake’s tenderness and rich texture. The full-fat content is essential for achieving the desired moistness and flavor. Heavy whipping cream is used to create both the light and airy filling and the luscious Nutella buttercream.
• Coffee: It’s a well-known secret among bakers: coffee has an incredible ability to deepen and enhance the flavor of chocolate. While you won’t taste coffee specifically, it amplifies the chocolate notes, adding a layer of complexity and richness that simple water cannot. If you prefer, you can use 1 tablespoon of espresso powder mixed into the dry ingredients, then use water, or simply use hot water as a last resort, but for the most profound chocolate flavor, coffee is highly recommended.
• Nutella: The star of the show! A generous amount of Nutella, or your favorite chocolate hazelnut spread, is central to this recipe. It’s incorporated into both the decadent filling, providing a smooth, nutty sweetness, and the creamy, irresistible Nutella frosting that coats the entire cake. Make sure to use a good quality spread for the best results.
• Hazelnuts: Whole hazelnuts are toasted and then chopped, serving a dual purpose. Firstly, they are mixed into the cake filling to provide a wonderful textural contrast – a delightful crunch against the soft cake and creamy spread. Secondly, toasting them before chopping intensifies their natural, earthy flavor, ensuring that the hazelnut notes are prominent and delicious throughout the cake.
• Powdered Sugar: Also known as confectioners’ sugar, this finely milled sugar is crucial for creating the smooth, stable, and spreadable texture of the Nutella buttercream. Its fine consistency dissolves easily, preventing any grittiness and resulting in a perfectly silky frosting.
• Eggs & Egg Yolks: While not explicitly listed in the intro, the recipe card highlights 2 large eggs and 2 large egg yolks. These are essential for structure, moisture, and richness in the chocolate cake batter. Always ensure they are at room temperature for optimal mixing and a smoother batter.

For a complete list of precise measurements and quantities, please refer to the detailed recipe card below.

Creative Substitutions and Exciting Variations

While this chocolate hazelnut cake recipe is perfect as is, we understand the desire for customization and dietary flexibility. Here are some thoughtful substitutions and exciting variations you can try to make this cake your own, ensuring it perfectly suits your taste and needs.

• Greek Yogurt for Sour Cream: If you’re out of sour cream or simply prefer it, full-fat Greek yogurt can be used as a direct substitute in the cake batter. It will provide a similar tanginess and moisture, contributing to a tender crumb.
• Hot Water Instead of Hot Coffee: For those who prefer to avoid caffeine or don’t have coffee on hand, hot water can be used in place of hot coffee in the cake batter. While coffee enhances the chocolate flavor significantly, water will still provide the necessary liquid without altering the cake’s structure.
• Chocolate Ganache Filling: For an even deeper chocolate experience, consider filling the cake layers with a rich chocolate ganache instead of Nutella. You can still mix in chopped roasted hazelnuts for that delightful textural element.
• Nutella Mousse Filling: Elevate the filling with a light and airy Nutella mousse. This variation creates a more delicate interior that beautifully complements the dense cake layers and creamy buttercream.
• Ferrero Rocher Delight: To amplify the hazelnut-chocolate theme, chop up some Ferrero Rocher candies and mix them into the cake filling. The wafer and hazelnut bits will add an extra layer of crunch and flavor. You can also top the finished cake with whole Ferrero Rocher for a stunning presentation. If you have any leftover, why not try making these incredible Ferrero Rocher brownies?
• Adjusting Buttercream Consistency: If your Nutella buttercream is too thick, you can thin it out by adding a tablespoon of water or milk at a time until it reaches your desired spreadable consistency. Conversely, if it’s too thin, gradually add more powdered sugar.

Always remember that while substitutions can work, they might slightly alter the final taste and texture of the cake. It’s always best to experiment with small batches if you’re unsure.

Understanding Cocoa Powder: Natural vs. Dutch-Processed

When it comes to baking, not all cocoa powders are created equal, and understanding their differences is crucial for achieving the desired outcome in your recipes. Cocoa powder plays a significant role in both the flavor and color of your chocolate bakes, and its interaction with leavening agents (like baking soda and baking powder) can vary greatly.

It’s important to note that you cannot always substitute different types of cocoa powder equally in every recipe, as their distinct properties react differently with specific leaveners. However, for this particular chocolate hazelnut cake, you’ll find that you can generally interchange natural and Dutch-processed cocoa powder without drastically affecting the final bake. This is usually true for recipes using less than 1 cup of cocoa powder, where the impact on leavening is less critical.

Natural Cocoa Powder

This is the most common type of cocoa powder you’ll find in grocery stores. It’s light in color and has a naturally acidic pH. Natural cocoa powder produces a very robust, intense chocolate flavor that is often described as slightly fruity or sharp. Because of its acidity, it typically reacts with baking soda to create lift in baked goods.

Dutch-Processed Cocoa Powder

My personal favorite and the variety used predominantly in my chocolate recipes, Dutch-processed cocoa powder has been treated with an alkalizing agent to reduce its acidity. This process results in a darker color and a milder, more mellow, and perfectly balanced chocolate flavor. It’s less “in your face” and offers a smoother, richer taste that I find complements other flavors beautifully, making it ideal for this chocolate hazelnut cake. Since it’s neutral, it often pairs with baking powder or a combination of baking soda and an acidic ingredient.

Black Cocoa Powder

Used in special recipes like my black velvet cake, black cocoa powder is the darkest of all cocoa varieties, giving bakes a dramatic, almost black hue. Despite its intense color, it has a surprisingly mellow chocolate flavor, very reminiscent of Oreo cookies. It’s a fantastic choice for Halloween treats or visually striking desserts like black hot chocolate.

Beyond its flavor and color, cocoa powder also acts as a powerful drying agent in batters. To unlock its full chocolate potential, it needs to absorb a significant amount of liquid – a process known as “blooming.” This is why many chocolate cake recipes, including this one, feature a relatively liquidy batter; it allows the cocoa to fully hydrate and develop that deep, rich chocolate flavor. Rest assured, with the correct balance of cocoa and leaveners, this seemingly thin batter will bake up into a perfectly moist and tender cake.

Essential Tools for Cake Decorating Success

While delicious flavor is paramount, a beautifully decorated cake adds to the overall experience. Having the right tools on hand can make the decorating process much smoother and more enjoyable, even for beginners. Here’s a list of indispensable equipment that will help you achieve a professional-looking finish for your chocolate hazelnut cake:

• Cake Boards: These sturdy cardboard circles provide a stable base for your cake, making it easier to move, assemble, and decorate without damaging the delicate layers. They are particularly helpful for transferring a finished cake.
• Offset Spatula: An offset spatula, with its angled blade, is invaluable for smoothly spreading frosting over the top and sides of your cake layers. The offset handle keeps your knuckles from dragging in the frosting, ensuring a clean and even application.
• Cake Scraper: For achieving perfectly straight, smooth sides on your frosted cake, a cake scraper is essential. It allows you to scrape away excess frosting and create a beautifully polished finish.
• Piping Bags: Whether you’re creating a frosting dam, adding decorative borders, or crafting intricate designs, piping bags offer precision and control. They come in various sizes and can be used with different tips.
• Piping Tips: A good set of piping tips will allow you to create a wide array of decorative effects, from simple stars and rosettes to elegant shell borders, adding a professional flourish to your cake.
• Revolving Cake Stand: While not strictly necessary, a revolving cake stand is an incredibly helpful tool for frosting and decorating. It allows you to rotate the cake smoothly, ensuring even coverage and easy access to all sides without having to constantly reposition yourself or the cake.

Step-by-Step Guide: Crafting Your Chocolate Hazelnut Cake

Making this irresistible chocolate hazelnut cake might seem elaborate, but by following these clear, step-by-step instructions, you’ll create a show-stopping dessert with ease. Each stage is crucial for achieving the perfect balance of moist cake, nutty filling, and creamy frosting.

Five: Bake and Cool Cake Layers. Divide the prepared batter evenly between two greased and parchment-lined 8-inch cake rounds. Bake them in a preheated oven until a toothpick inserted into the center comes out clean. Once baked, allow the cakes to cool in their pans on a wire rack for about 10 minutes before carefully inverting them, removing the parchment paper, and letting them cool completely on the wire racks. Patience is key here; frosting warm cakes will lead to a melted mess!

Six: Prepare Hazelnut Filling. In a bowl, combine the Nutella and cold heavy whipping cream. Beat them together with a hand mixer, starting on low speed and gradually increasing, until the mixture is light, fluffy, and slightly aerated. Gently fold in the toasted and finely chopped hazelnuts. This creates a delightful, nutty filling with a wonderful crunch that perfectly complements the soft cake. Make sure your heavy cream is cold for the best whipping results.

Seven: Create Nutella Buttercream Base. In the bowl of a stand mixer fitted with a paddle attachment (or using a hand mixer), beat the room temperature unsalted butter and Nutella together on medium speed for about 2 minutes. Continue until the mixture is light, smooth, and well combined. This initial creaming step ensures a fluffy foundation for your buttercream.

Eight: Finish the Buttercream. Add the powdered sugar, cold heavy cream, vanilla extract, and a pinch of kosher salt to the butter-Nutella mixture. Start by beating on low speed for about 30 seconds to incorporate the powdered sugar without creating a cloud. Then, increase the speed to medium-high and continue beating for another 2 minutes until the buttercream is gloriously light, fluffy, and easily spreadable. Adjust consistency by adding more cream or powdered sugar as needed.

Nine: Pipe the Frosting Dam. Place the first leveled cake layer onto your serving platter or cake board. Using a piping bag filled with Nutella buttercream, pipe a sturdy dam around the very outside edge of the cake round. For extra security and to ensure it can hold all the delicious filling, pipe two layers for a taller, more robust dam.

Ten: Fill the Cake. Carefully spoon the hazelnut filling (prepared in step six) into the center of the frosting dam. Spread it evenly with an offset spatula or the back of a spoon, making sure it reaches the piped dam but doesn’t go over it. This creates a perfectly contained and generous layer of nutty, chocolatey goodness.

Eleven: Stack and Crumb Coat. Gently place the second leveled cake layer on top of the filling, pressing down lightly to secure it. Add a few large dollops of the remaining Nutella buttercream to the very top of the cake. Working from the center outwards, gently push the buttercream to the edges, then down the sides of the cake, covering the entire cake with a thin layer. This is your “crumb coat,” which traps any loose crumbs and creates a smooth base for the final frosting layer. Refrigerate the cake for 15 minutes to allow the crumb coat to set.

Twelve: Final Frosting and Garnish. Retrieve the cake from the fridge. Use the remaining buttercream to add a second, thicker layer of frosting, covering the entire cake completely. Use an offset spatula or cake scraper to smooth it out to your desired finish – whether perfectly smooth or with a rustic texture. For an extra touch of elegance and flavor, garnish your stunning chocolate hazelnut cake with delicate drizzles of melted Nutella and a sprinkle of additional chopped hazelnuts. Now it’s ready to be sliced and enjoyed!

Mastering Your Bake: Expert Tips for Success

Achieving a perfect chocolate hazelnut cake is within your reach with these invaluable expert tips. These simple but effective techniques will help ensure your cake is moist, flavorful, and beautifully presented every single time.

• Embrace Room Temperature Ingredients: This is a golden rule in baking, especially for cakes! Ensure all your dairy ingredients (sour cream, milk) and eggs are at room temperature. Cold ingredients don’t emulsify as well with butter and sugar, leading to a lumpy batter and a less uniform cake texture. Taking them out of the fridge about 30-60 minutes before you start baking makes a huge difference.
• Always Sift Dry Ingredients: Cocoa powder, flour, and leavening agents can often contain small lumps. Sifting your dry ingredients together is not just about removing these clumps; it also aerates them, which makes them easier to mix and contributes to a lighter, more tender cake crumb. Even a quick whisking might not break up all the fine cocoa powder clumps.
• Line Cake Pans with Parchment Paper: For effortless cake release and perfectly intact layers, always line the bottoms of your cake pans with parchment paper rounds. After greasing the pans, cut out circles of parchment paper to fit the bottom, then grease the parchment as well. This creates a non-stick barrier that prevents sticking and makes removal a breeze.
• Level Off Domed Cake Tops: After your cake layers have cooled, it’s common for them to have a slight dome in the center. For a professional-looking, perfectly even layer cake, use a long serrated knife (like a bread knife) to carefully slice off the domed tops, making each layer perfectly flat. This ensures a stable and attractive stacked cake.
• Cool Cake Layers Completely: Patience is a virtue in baking, particularly when it comes to cooling. Allow your cake layers to cool completely before you even think about assembling or frosting them. Attempting to frost a warm or even slightly warm cake will cause your beautiful buttercream to melt and slide right off, turning your masterpiece into a messy disaster.
• Keep Your Serving Platter Clean: To maintain a pristine presentation, place small strips of parchment paper or wax paper around the edges of your serving platter, just under the bottom cake layer, before you start frosting. This acts as a barrier, catching any stray frosting drips. Once you’re done decorating, gently pull out the strips, revealing a perfectly clean platter.
• Protect Cut Cake Sides: Once your cake is sliced, the exposed cake and filling can dry out quickly. To keep your cake moist and prevent the delicious filling from seeping out, press pieces of plastic wrap or parchment paper directly against the cut sides of the cake before storing. This locks in moisture and preserves freshness.

Common Questions About This Chocolate Hazelnut Cake

Here are some frequently asked questions to help you confidently bake and enjoy your delicious chocolate hazelnut cake.

Storing Your Delicious Chocolate Hazelnut Cake

Proper storage is essential to keep your chocolate hazelnut cake tasting fresh and delicious for as long as possible. Follow these guidelines to maintain its moistness and rich flavor.

Short-Term Storage

You can store the assembled cake at room temperature for up to one day. It’s important to note that only the cut and exposed cake pieces need to be covered with plastic wrap or a piece of parchment paper to prevent them from drying out. The rest of the cake, fully enclosed by the generous layer of Nutella buttercream, is naturally protected from the air.

After the first day, for extended freshness, move the cake to the refrigerator. It will keep well in the fridge for an additional 2-3 days. Before serving, always allow slices of the cake to come to room temperature for at least 30-60 minutes. This brings the buttercream and filling back to their optimal, creamy consistency, enhancing the overall taste and texture.

Freezing for Long-Term Enjoyment

This chocolate hazelnut cake freezes beautifully, allowing you to enjoy it weeks or even months later. Here’s how to freeze both slices and a whole cake:

To freeze individual slices: Cut the cake into desired slices. Place them on a baking sheet lined with parchment paper and flash-freeze them for about 1-2 hours until firm. Once firm, wrap each slice completely and tightly in plastic wrap, ensuring no air exposure. Then, transfer the wrapped slices to a freezer-safe ziptop bag or airtight container. These slices can be stored for up to two months. To enjoy, unwrap completely and thaw at room temperature for a few hours before indulging.

To freeze the whole cake: If you wish to freeze an entire cake, first place the unfrosted or crumb-coated cake in the freezer until it is firm (flash-freeze). Once firm, wrap it completely in multiple layers of plastic wrap, followed by a few layers of aluminum foil. This double-layer protection is crucial to prevent freezer burn. The whole cake can be frozen for up to two months. When ready to serve, unwrap the cake completely and thaw it overnight in the refrigerator, then bring it to room temperature before enjoying or applying a final layer of frosting.

Discover More Irresistible Chocolate Cake Recipes

If you’re a true chocolate connoisseur, your culinary journey doesn’t have to end with this incredible chocolate hazelnut cake. We have a treasury of other delightful chocolate cake recipes waiting for you to explore. Each one offers a unique twist on this classic dessert, promising new flavors and exciting baking adventures. Indulge your cravings and expand your baking repertoire with these fan favorites:

Important Notes When Cooking with The Cozy Plum

At The Cozy Plum, we’re dedicated to helping you achieve baking success. Here are a few key things to remember that apply across many of our recipes, ensuring consistent and delicious results every time:

• All recipes are meticulously crafted with Diamond Crystal kosher salt. This is the least salty variety of kosher salt. If you are using Morton’s kosher salt or sea salt, you will need to reduce the amount of salt by half, as these varieties are approximately twice as salty. Please avoid using standard table salt, as its fine grain and stronger salinity can drastically alter the balance of flavors.
• To achieve the most accurate and consistent results in baking, we highly recommend using a digital scale and baking by weight (metric measurements). You can easily switch between US Customary and Metric measurements using the toggle provided on the recipe card below. While cups are convenient, weight measurements eliminate inconsistencies caused by varying packing densities of ingredients.
• You can easily scale any recipe up or down using the ‘1X’, ‘2X’, ‘3X’ buttons found on the recipe card. Please be aware that these buttons only adjust ingredient quantities; they do not automatically modify baking times. Always use your judgment and monitor your bakes closely when scaling a recipe.
• If you wish to bake this recipe in a different sized pan, our handy pan size converter can help you adjust the recipe quantities accordingly, ensuring your cake bakes properly.

Chocolate Hazelnut Cake

Callan Wenner

Cake

• ▢ 2 cups all-purpose flour
• ▢ 2 cups granulated sugar
• ▢ ¾ cup dutch-processed cocoa powder
• ▢ 1½ teaspoons baking soda
• ▢ 1 teaspoon baking powder
• ▢ 1 teaspoon kosher salt
• ▢ 2 large eggs room temperature
• ▢ 2 large egg yolks room temperature
• ▢ ½ cup vegetable oil
• ▢ ½ cup unsalted butter melted
• ▢ ¾ cup sour cream room temperature
• ▢ ¼ cup whole milk room temperature
• ▢ 1 cup coffee or water steaming hot

Filling

• ▢ ½ cup chopped hazelnuts
• ▢ ⅔ cup Nutella
• ▢ ¼ cup heavy whipping cream cold

Frosting

• ▢ ¾ cup unsalted butter room temperature
• ▢ ¾ cup Nutella
• ▢ 3 cups powdered sugar
• ▢ ¼ cup heavy cream cold
• ▢ 1 teaspoon vanilla
• ▢ ⅛ teaspoon kosher salt

Chocolate Cake

• Preheat your oven to 350℉/177℃. Prepare two 8-inch round cake pans by greasing them thoroughly and lining the bottoms with parchment paper rounds. This ensures your cakes release easily and bake evenly. Set aside.
• In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, Dutch-processed cocoa powder, baking soda, baking powder, and kosher salt. Ensure there are no lumps and all ingredients are well combined.
  2 cups all-purpose flour, 2 cups granulated sugar, ¾ cup dutch-processed cocoa powder, 1½ teaspoons baking soda, 1 teaspoon baking powder, 1 teaspoon kosher salt
• In a separate medium bowl, whisk together the room temperature eggs and egg yolks, vegetable oil, melted unsalted butter, room temperature sour cream, and whole milk until the mixture is smooth and fully blended. Pour this wet mixture into the dry ingredients and mix with a spatula until just incorporated, being careful not to over-mix.
  2 large eggs, 2 large egg yolks, ½ cup vegetable oil, ½ cup unsalted butter, ¾ cup sour cream, ¼ cup whole milk
• Carefully pour the steaming hot coffee (or water) into the batter. Mix gently until it is fully combined and a thin, consistent batter forms. Be mindful not to over-mix or splash the liquid over the sides of the bowl.
  1 cup coffee or water
• Divide the batter evenly between the two prepared cake pans. Bake on the middle oven rack for 30-35 minutes, or until a wooden toothpick inserted into the center of the cakes comes out clean. Let the cakes cool in their pans on a wire rack for 10 minutes. Then, carefully invert them, remove the parchment paper, and transfer them back to the wire racks to cool completely before frosting.

Filling

• Add the chopped hazelnuts to a large frying pan. Toast them over medium-low heat, tossing frequently, until they are lightly golden brown and wonderfully fragrant. This step significantly enhances their nutty flavor. Transfer the toasted nuts to a cutting board to cool completely, then chop them finely if not already.
  ½ cup chopped hazelnuts
• In a large bowl, combine the Nutella and cold heavy cream. Begin mixing slowly with a hand mixer to incorporate the ingredients, then increase the speed to high and whip for about 2 minutes until the mixture becomes noticeably lighter in color and airier in texture. Gently fold in the cooled, finely chopped toasted hazelnuts.
  ⅔ cup Nutella, ¼ cup heavy whipping cream

Nutella Buttercream

• In the bowl of a stand mixer fitted with a paddle attachment (or using a hand mixer), beat the room temperature unsalted butter and Nutella on medium speed. Continue beating for about 2 minutes until the mixture becomes wonderfully light, fluffy, and perfectly smooth. Scrape down the sides of the bowl as needed to ensure everything is well combined.
  ¾ cup unsalted butter, ¾ cup Nutella
• Add the powdered sugar, cold heavy cream, vanilla extract, and kosher salt to the butter-Nutella mixture. Start beating on low speed for about 30 seconds, just until the powdered sugar is incorporated and prevents a sugary cloud. Then, increase the speed to medium-high and beat for another 2 minutes until the buttercream is incredibly light, airy, and easily spreadable. This creates the perfect creamy texture for frosting.
  3 cups powdered sugar, ¼ cup heavy cream, 1 teaspoon vanilla, ⅛ teaspoon kosher salt
• To achieve the perfect consistency, if your frosting appears too thick, add 1 tablespoon of heavy cream at a time, mixing well after each addition, until it reaches a smooth, spreadable texture. Conversely, if the frosting is too thin, gradually add ¼ cup of powdered sugar at a time until it thickens to your desired consistency.

Assembly

• Using a serrated knife, carefully slice off the domed tops of your cooled cake rounds, ensuring they are as level and flat as possible. Place the first leveled cake layer onto your chosen serving platter or cake board.
• Using a piping bag filled with the Nutella buttercream, pipe a sturdy circle around the very outside edge of the cake round. For extra stability and to prevent the filling from oozing out, create two layers for a robust frosting dam. Then, spoon the chocolate hazelnut filling into the center of this dam and spread it evenly with an offset spatula until it gently meets the buttercream border.
• Carefully place the second cake layer directly on top of the filling. Add a few generous dollops of the remaining Nutella buttercream onto the top of this layer. Working from the middle outwards, gently push the buttercream to the edges, then down the sides of the cake, covering the entire cake with a thin, even layer. This is your initial “crumb coat” which seals in any loose crumbs for a smooth finish.
• Using an offset spatula or a cake scraper, smooth out the crumb coat into a very thin, even layer across the top and sides of the cake. This step is crucial for preventing crumbs from appearing in your final frosting layer. Once smoothed, refrigerate the cake for 15 minutes to allow the crumb coat to firm up.
• Remove the cake from the refrigerator. Use the remaining buttercream to apply a second, thicker, and final layer of frosting to cover the entire cake. Smooth it out beautifully with your offset spatula or cake scraper until you achieve your desired finish. If you have any extra buttercream, you can use a piping bag and a decorative tip to add elegant borders or other decorative piping for a stunning presentation (this step is entirely optional but highly recommended!).

The provided nutritional information is an estimate per serving. Accuracy is not guaranteed.