This chocolate hazelnut cake is two moist 8 inch chocolate layers filled with a Nutella ganache and covered in a dark chocolate ganache that drips down the sides. It takes about 2 hours including cooling and chilling, and cuts into 12 slices. The step that matters most is chilling the hazelnut filling until it is spreadable but still soft, so the top layer sits on it without sliding.
The layers are a one bowl style oil cake made with cocoa, buttermilk, and hot coffee. Toasted hazelnuts and chocolate curls go on top.
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Try the Recipe Converter →- Serves: 12 slices from a two layer 8 inch cake
- Time: 25 minutes prep, 30 to 35 minutes baking at 350°F (175°C), about 1 hour cooling and chilling
- Pans: two 8 inch round pans, at least 2 inches deep, greased and lined
- Filling ratio: 1 cup heavy cream, 1 1/2 cups semi-sweet chips, 1/2 cup hazelnut spread
- Ganache ratio: 1 cup heavy cream to 1 1/2 cups semi-sweet or dark chips
- Keeps: 3 days in the fridge; unfilled layers freeze for a month
How Much Hazelnut Flavor Does This Cake Have?
Medium. The hazelnut comes from 1/2 cup of hazelnut spread in the filling and the toasted nuts on top, so the cake tastes like chocolate first and Nutella second. I use Nutella because it melts into the warm ganache evenly without separating.
For a stronger hazelnut cake, stir 1/2 teaspoon hazelnut extract into the filling, and press extra chopped toasted hazelnuts around the bottom edge. If you want hazelnut to lead, my nut-forward hazelnut layer cake has toasted hazelnuts in the crumb and a hazelnut buttercream. And yes, hazelnut frosting works on chocolate cake: a Nutella buttercream can replace the ganache top if you prefer a fluffy finish.
Compared with a flourless chocolate cake, which is dense and fudgy all the way through, this one is a soft, open crumb with two creamy layers. It is the lighter choice after a big holiday dinner.
Oil, Buttermilk, and Hot Coffee in the Layers
I have baked this cake with both oil and melted butter. Butter tastes richer, but it firms up in the fridge, and this cake spends time in the fridge. The oil layers stayed soft after two days chilled and did not tear when I spread the filling. That is why the card uses 1/2 cup vegetable oil.
Buttermilk adds a little tang and a tender crumb. No buttermilk? Put 1 tablespoon lemon juice or white vinegar in a measuring cup, add milk to the 1 cup line, and let it sit for 10 minutes. Have it and the eggs at room temperature so the oil does not seize into streaks.
The hot coffee deepens the cocoa without making the cake taste like coffee. Hot water works if you are baking for kids or anyone avoiding caffeine.
Baking Two 8 Inch Chocolate Layers
Heat the oven to 350°F and grease and line two 8 inch round pans. Whisk the flour, cocoa, baking powder, baking soda, and salt in a large bowl until no streaks of cocoa remain.
In another bowl, whisk the sugar, oil, eggs, and vanilla until smooth, then stir in the buttermilk. Add the dry ingredients and mix only until combined.
Pour in the hot coffee last and stir. The batter turns thin, almost pourable like heavy cream. That is right, so do not add flour.
Divide it evenly between the pans and bake for 30 to 35 minutes, until a toothpick in the center comes out clean and the top springs back when pressed. Cool the layers completely, at least an hour. If they domed, trim the tops flat with a serrated knife so the cake stacks level.
Making the Nutella Ganache Filling
The filling is a soft chocolate ganache with hazelnut spread stirred in: 1 cup heavy cream, 1 1/2 cups semi-sweet chips, and 1/2 cup Nutella. Heat the cream until small bubbles appear at the edge, pour it over the chips, and leave it alone for 5 minutes. Then stir from the center out until glossy and add the hazelnut spread.
Chill it for about 20 minutes. It is ready when it holds a soft peak on a spatula, like thick pudding. Gone too firm? Stir it hard for a minute or warm it for 5 seconds in the microwave. Still runny after 20 minutes? Give it another 10, stirring once.
Want chopped nuts in the middle layer? My chocolate hazelnut cake filling adds toasted hazelnuts, and the Nutella cake filling with mascarpone sets firmer for taller cakes.
Stacking So the Filling Stays Inside
Set the first layer on your serving plate, cut side up. Spread the filling to about 1/2 inch from the edge. This is a generous amount of filling, and the weight of the top layer pushes it out to the rim. Spread it all the way and it squeezes over the side.
Place the second layer on top, flat side up, and press gently with your palm. Chill the cake while you make the ganache, at least 15 minutes. A cold cake helps the ganache set where it lands.
When Is the Ganache Ready to Pour?
Heat the second cup of cream until just simmering and pour it over 1 1/2 cups semi-sweet or dark chips. I prefer dark here, because it balances the sweeter filling. Stir until glossy, then let it cool for about 10 minutes. My chocolate ganache recipe has more on ratios if you want it thicker or thinner.
To test, spoon one drip over the edge of the chilled cake. If it runs to the plate, wait 5 minutes. When it stops about halfway down the side, it is ready. Pour the rest into the center and nudge it toward the edges with a spoon so it falls over in drips. Too thick to drip? Set the bowl over warm water and stir for a minute.
Toasted Hazelnuts and Chocolate Curls on Top
Toast the hazelnuts at 350°F for 10 to 12 minutes, until fragrant and the skins crack. Wrap them in a kitchen towel while hot and rub; most of the papery, bitter skins slip off. Chop 1/2 cup for the top and keep a few whole for the center, then add chocolate curls if you like.
Chill the finished cake for 30 minutes before slicing so the layers and ganache set. Slice with a knife dipped in hot water and wiped dry between cuts. It goes well with black coffee or lightly sweetened whipped cream.
A Two Day Plan for a Party Cake
Day 1: bake the layers, cool them, wrap them in parchment, and leave them at room temperature overnight. They firm up and are easier to level and stack. The layers also freeze, tightly wrapped, for up to a month; thaw them fully before filling.
Day 2: make the filling, stack, glaze, and chill. The whole cake keeps in the fridge for up to 3 days under a cake dome or loosely tented with foil, so you can finish it the day before a Christmas or birthday party.
Chocolate Hazelnut Cake Questions
Can I make this as cupcakes?
The batter can bake as cupcakes, but they need a much shorter bake, so check them early. For a cupcake version with its own timing, use my chocolate hazelnut truffle cupcakes.
Can I use 9 inch pans?
Yes. The layers will be thinner, so start checking at about 25 minutes.
What else can I bake with leftover Nutella?
Try chocolate hazelnut thumbprint cookies or Nutella cinnamon rolls.
Pin this chocolate hazelnut cake to your celebration cakes board. If you bake it, tell me in the comments how you finished the top and whether you added the hazelnut extract.
Chocolate Hazelnut Cake Recipe
This chocolate hazelnut cake is a two layer 8 inch chocolate cake made with cocoa, buttermilk, oil, and hot coffee, filled with a Nutella ganache and topped with a glossy dark chocolate ganache. It takes about 2 hours including cooling and chilling and serves 12, with a soft, moist crumb and a creamy hazelnut layer in the middle. The hazelnut filling is chilled until spreadable before stacking, so the top layer stays put and the ganache drips cleanly down the cold cake. Serve it as a birthday cake, a Christmas or New Year dessert, or a chocolate cake with hazelnut filling for any party, finished with toasted hazelnuts and chocolate curls. It keeps 3 days in the fridge.
Ingredients
- FOR THE CAKE LAYERS
- 1 ¾ cups all-purpose flour
- 1 ½ teaspoons baking powder
- ½ teaspoon baking soda
- ½ teaspoon salt
- ¾ cup unsweetened cocoa powder
- 1 ¾ cups granulated sugar
- ½ cup vegetable oil
- 2 large eggs, room temperature
- 1 teaspoon pure vanilla extract
- 1 cup buttermilk, room temperature
- 1 cup hot coffee (or hot water)
- FOR THE HAZELNUT FILLING
- 1 cup heavy cream
- 1 ½ cups semi-sweet chocolate chips
- ½ cup hazelnut spread (such as Nutella)
- FOR THE GANACHE TOPPING
- 1 cup heavy cream
- 1 ½ cups semi-sweet or dark chocolate chips
- DECORATIONS (OPTIONAL)
- ½ cup chopped toasted hazelnuts
- Whole hazelnuts for garnish
- Chocolate curls or shavings
Instructions
MAKE THE CAKE LAYERS: Preheat oven to 350°F (175°C). Grease and line two 8-inch round cake pans. In a large bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt. In another bowl, whisk sugar, oil, eggs, and vanilla until smooth. Stir in the buttermilk, then add the dry ingredients and mix until just combined. Pour in the hot coffee and stir until the batter is smooth and slightly thin. Divide evenly between the pans and bake for 30–35 minutes, or until a toothpick inserted comes out clean. Allow cakes to cool completely.
PREPARE THE HAZELNUT FILLING: Heat the cream in a small saucepan until just beginning to simmer. Pour over the chocolate chips in a heatproof bowl and let sit for 5 minutes. Stir until smooth, then add the hazelnut spread and mix until creamy. Refrigerate for 20 minutes, or until thick enough to spread.
ASSEMBLE THE CAKE: Place one cake layer on a serving plate. Spread the hazelnut filling evenly over the top. Place the second cake layer on top, pressing gently. Chill the cake while preparing the ganache.
MAKE THE GANACHE: Heat the cream in a saucepan until just simmering. Pour over the chocolate chips and stir until glossy and smooth. Allow to cool for about 10 minutes until slightly thickened but still pourable.
FINISH THE CAKE: Pour the ganache over the chilled cake, letting it drip naturally down the sides. Sprinkle with chopped hazelnuts and top with whole hazelnuts and chocolate curls if desired. Chill for 30 minutes before slicing to set the layers and topping.
Notes
Chill the hazelnut filling only until it holds a soft peak; if it sets too firm, stir it hard or warm it for 5 seconds. Spread the filling to 1/2 inch from the edge so it does not squeeze out under the top layer. Test the ganache with one drip on the chilled cake before pouring; it should stop about halfway down the side. The cake layers can be baked a day in advance, wrapped, and stored at room temperature, or frozen for up to a month. For a stronger hazelnut flavor, add 1/2 teaspoon hazelnut extract to the filling. Chill the finished cake 30 minutes before slicing and store it in the fridge for up to 3 days.
Nutrition Information
Yield
12Serving Size
1Amount Per Serving Calories 740Total Fat 47gSaturated Fat 18gTrans Fat 1gUnsaturated Fat 25gCholesterol 82mgSodium 285mgCarbohydrates 77gFiber 5gSugar 53gProtein 10g
This picture shows a frosted cake with ganache poured over, but the recipe does not call for frosting the cake first. Is the hazelnut filling recipe enough to frost the entire cake or is that a step that was not included??
Great eye, TJ. The cake in the photo isn’t frosted underneath — that smooth look comes from pouring the ganache over a fully chilled cake. The hazelnut filling is only used between the layers, not on the outside, and the recipe reflects that.
If you prefer a frosted finish under the ganache, you could double the filling and use it to coat the whole cake before pouring. But as it stands, there’s no step missing just a well-chilled cake and a clean ganache pour that gives it that polished look 😊