This elegant — and deceptively simple — hazelnut cake with chocolate hazelnut ganache and buttercream (OMG) is sure to make jaws drop. Serve it as a birthday cake, for a special anniversary, or just because!
All images and recipe via Erin Bakes
The hazelnut cake is a no-fuss, no-mixer-needed recipe and the ganache does double duty as a cake filling and as the flavoring for the buttercream. Creating the stunning chocolate buttercream flower topper doesn’t require an advanced pastry degree — just the right piping tip and a little bit of patience.
Chocolate hazelnut layer cake recipe
For the cake:
Yields three 6″ round cake layers.
- 3 cups cake flour
- 2 cups coarsely ground toasted hazelnuts (reserve 3 whole hazelnuts for garnish)
- 1¾ cups granulated sugar
- 1½ teaspoons baking powder
- 1 teaspoon kosher salt
- 4 large eggs
- 1 cup milk
- ½ cup vegetable oil
- 4 tablespoons unsalted butter, melted
- 1 tablespoon pure vanilla extract
- 3 tablespoons Frangelico or hazelnut liquor (or 1 tablespoon hazelnut extract)
For the ganache:
Yields about 1 cup of ganache
- ½ cup heavy cream
- ½ cup chocolate hazelnut cream (like Nutella)
- 8 ounces dark chocolate, chopped
- 1 tablespoon Frangelico (or 1 teaspoon hazelnut extract)
For the Swiss meringue buttercream:
Yields about 5 cups of buttercream
- 1 cup pasteurized egg whites
- 2 cups granulated sugar
- 2 pounds room temperature unsalted butter, cubed
- 2 tablespoons pure vanilla extract
- ½ cup of the ganache
- Three 6″ round cake pans
- Offset icing spatula
- Straight icing spatula
- Bench scraper (optional)
- Large piping bag
- St. Honore Piping Tip (Ateco #882)
Baking the cake and the ganache
Position a rack in the center of the oven and preheat the oven to 350 F. Grease and flour three 6″ round cake pans. Set aside while you prepare the batter.
Add cake flour, 1 cup of hazelnuts, sugar, baking powder and salt to a large mixing bowl and stir until thoroughly combined.
In a smaller bowl or measuring cup, whisk together the eggs, milk vegetable oil, melted butter, vanilla and Frangelico.
Pour the wet mixture over the dry and whisk until just combined. Switch to a spatula to finish mixing if the batter gets too thick for the whisk.
Divide the batter evenly between the three prepared bans.
Bake for 40-45 minutes or until a toothpick inserted in to the center of the cake comes out clean or with a few crumbs sticking to it.
Set the cake pans on a rack until they are cool to the touch. Turn the cakes out of the pans and set them on a flat surface to continue cooling. Allow the cakes to cool completely before filling, about 30 minutes. Pop the cakes in the fridge if you want them to cool faster.
While the cakes are cooling, combine chopped chocolate, chocolate hazelnut cream and Frangelico in a large mixing bowl.
In a medium sauce pan, bring the heavy cream to a boil. Shut the heat off as soon as you see the first bubbles.
Pour the hot cream over the chocolate mixture and whisk until all the chocolate chunks have melted. Set the ganache aside at room temperature while you work on the buttercream.
Fill a small sauce pan one-third of the way up with water. Set the pan over high heat. Turn the heat down to medium-low once the water comes to a boil.
Combine egg whites and sugar in a medium heatproof bowl. Set the bowl on top of the sauce pan. Whisk the mixture every few minutes until the sugar has completely dissolved, about 5 minutes. Cook the mixture to 160 degrees F if you are using fresh egg whites. (Fresh egg whites will whip up much faster than pasteurized ones.)
Pour the egg white mixture into the bowl of a stand mixture fitted with the whisk attachment. Add the vanilla extract. Turn the mixture to high speed and whip it until the egg whites reach soft peaks.
Turn the mixer to low and add the butter to the meringue a few cubes at a time. Once all of the butter has been added, turn the mixer back up to high and whip until the buttercream is smooth and fluffy, about 5 minutes.
Turn the mixer back down to low speed and add the ganache. Mix until combined. Stop and scrape down the sides of the bowl with a rubber spatula as needed.
Assembling the cake
Use a serrated knife to level the domed tops of the cakes. Smear a dab of buttercream or ganache on a 6″ round cake board. Press one of the layers of cake onto the smear to adhere it to the cake board.
Use an offset spatula to spread a thin layer of ganache onto the layer of cake.
Top the ganache with roughly ½ cup of buttercream. Smooth the buttercream layer out with an offset spatula and top it with another layer of cake.
Repeat with another layer of ganache and buttercream. Top with the final layer of cake, cut side down.
Crumb coat the cake with a thin layer of buttercream. (Check out this tutorial for full step-by-step directions for crumb coating.)
Pop the cake in the fridge to allow the layers to firm up and the crumb coat to set, 20 minutes to overnight.
Finish the sides of the cake with a thicker coat of buttercream. Use a bench scraper or straight icing spatula to smooth the sides.
Use an offset spatula to spread approximately ¼ cup of ganache onto the layer cake. Don’t worry about making the top of the cake perfectly smooth — just clean up the edges.
Decorating the cake
Spread a small circle of ganache (about 2 tablespoons) in the center of the top of the cake. Sprinkle a smaller circle of chopped hazelnuts on top of the ganache. Position three hazelnuts to create the center of the large buttercream flower.
Fill a piping bag fitted with a large St. Honore tip with the remaining buttercream.
Hold the bag so that the slit in the tip is facing up. Position the tip so that the bottom edge sits just above the center of the cake.
Apply pressure to the bag and pipe a small arch of buttercream around the hazelnuts. Shortly before you get to the end of your first petal, release pressure and pull the tip down and away from the cake.
Start the next petal above this one about half way down. Repeat, overlapping petals, until the entire top of the cake is filled.
Scoop up some of the remaining chopped hazelnuts and press the nuts into the sides of the cake all the way around the bottom edge to create a border.
Slice in and enjoy immediately or allow the cake to sit at room temperature for up to 4 hours.
Store the cake in the fridge for up to three days lightly draped with plastic wrap or in a cake saver. Allow the cake to return to room temperature before serving.