Hazelnut Chocolate Mousse Cake

Nothing says 'decadent dessert' like a moist chocolate cake that's topped with hazelnuts does. Well, maybe an elegant bowl of rich, airy chocolate mousse or a creamy chocolate glaze might! So in the name of creating the most luxurious, luscious, chocolatey dessert possible, we combined all of those elements and came up with this hazelnut chocolate mousse cake. With just a little help from an empty paper towel roll, we're making the richest, moistest, most extravagant dessert there ever was! Serve this cake at your next dinner party and your guests will walk away speechless. And believe us, this is a must-try recipe for all of the chocaholics out there – we're hazelnuts about it!

Yield: 1
Prep Time: 90 minutes
Cooking Time: 30 minutes
Inactive Time: 27 hours
Difficulty Level: Moderate

You'll Need:

For the chocolate mousse:

  • 1 lb semi-sweet chocolate chips
  • ½ oz unflavored gelatin (1 tbsp unflavored gelatin powder or 4 gelatin sheets)
  • 3½ cups whipped cream
  • 2 egg yolks
  • 2 eggs
  • 1 pinch of salt

For the chocolate cake:

  • ½ cup sugar
  • 3 eggs
  • 1 cup flour
  • 2 tbsp cocoa powder
  • 1 tsp baking powder
  • 1 pinch of salt

For the chocolate mirror glaze:

  • 1 cup heavy cream
  • 1¾ cups sugar
  • 1¼ cups water
  • 1½ cups cocoa powder
  • ½ oz unflavored gelatin (1 tbsp unflavored gelatin powder or 4 gelatin sheets)


  • ⅔ cup hazelnuts
  • 1 empty paper towel roll
  • loaf pan

Here's How:

1. For the chocolate mousse, start by soaking the gelatin sheets in cold water if you're using them. Whisk the eggs and egg yolks over a double boiler until they become thick and creamy, then add the semi-sweet chocolate chips to the warm egg mixture. If you're using gelatin sheets, wring them out, then add the gelatin sheets or unflavored gelatin powder to the chocolate mixture. Fold in the whipped cream and a pinch of salt, transfer the chocolate mousse to the refrigerator, and let it chill.

2. Preheat the oven to 375°F and line a baking tray with parchment paper. For the chocolate cake, separate the eggs and beat the egg whites together with a pinch of salt until stiff. Beat the egg yolks together with the sugar until frothy. Stir together the flour, cocoa powder, and baking powder, then pass the mixture through a fine sieve straight into the egg yolk mixture and stir everything together. Carefully fold in the egg white mixture, then spread the cake batter evenly over the baking tray lined with parchment paper. Transfer the baking tray to the oven and bake the chocolate cake at 375°F for 6 minutes.

3. Cut open an empty paper towel roll, unroll it, and place it in the bottom of a loaf pan to create a domed base. Cut a rectangle out of the center of the chocolate cake and place it on the paper towel roll in the loaf pan. Cut a segment the size of the bottom of the loaf pan out of the chocolate cake and set it aside for later. Crumble the rest of the chocolate cake into small crumbs and set them aside for later.

4. Spoon a layer of chocolate mousse onto of the layer of chocolate cake in the loaf pan, then sprinkle the cake crumbs on top. Repeat this process 2–3 times until the pan is filled, alternating between chocolate mousse and cake crumbs, making sure to save some chocolate mousse for later. Place the piece of chocolate cake on top. Press down lightly on the base of the cake so that it sits firmly on top of the layers of chocolate mousse, transfer the loaf pan to the freezer, and freeze for 3 hours.

5. Once the cake has frozen, cover the loaf pan with a cutting board and flip the pan over to remove the cake. Remove the paper towel roll, spread the remainder of the chocolate mousse over the surface of the cake, and place the hazelnuts on top. Transfer the cake to the refrigerator and chill for 24 hours.

6. The following day, soak the gelatin sheets in cold water if you're using them and bring the heavy cream, water, and sugar to a boil for the chocolate mirror glaze. Add in the cocoa powder and whisk all of the ingredients together. Heat the mixture to 215°F, then pour it into a measuring cup and let it cool down to 140°F. Wring out the gelatin sheets if you're using them, then add the unflavored gelatin powder or gelatin sheets to the chocolate mixture and whisk everything together until the gelatin dissolves completely, being careful to avoid making any bubbles.

7. Place the cake on a cooling rack positioned over a baking tray, and once the chocolate mirror glaze is about 95°F, pour it over the cake.

The light and airy texture mixed with the rich, moist decadence of this hazelnut chocolate mousse cake make it unlike any other dessert you've had before. And the literal icing on the cake is the gorgeous chocolate mirror glaze, which puts this cake off the chocolate charts!

Get the recipe for the Caramel Nut Cake featured in the bonus video.


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