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A Slice of Triple Chocolate Mousse Cake
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Triple Chocolate Mousse Cake

Fanny Lam's original recipe was pure and simple, which is a lovely thing in a day of over complicated recipes, but I decided to add a bit of coffee flavor to this Triple Chocolate Mousse Cake, to recreate the flavor of my childhood memory.
Course: Desserts
Author: Fanny Lam from Oh Sweet Day!

Ingredients

Chocolate Sponge Cake

  • 1/2 cup (65g) all-purpose flour
  • 2 tbsp cocoa powder
  • 1/4 tsp salt
  • 3 large eggs room temperature
  • 1/2 cup (113g) granulated sugar
  • 1 tbsp oil
  • 1/2 tsp vanilla extract

Coffee Soak for Baked Cake Layer

  • 2 tbsp BREWED coffee
  • 2 tbsp simple syrup

Chocolate Mousse

  • 200 g bittersweet chocolate finely chopped
  • 1 tbsp butter
  • 1/4 cup water or use coffee or a coffee flavored liqueur, like Kahlua
  • 3 eggs separated
  • 1 tbsp granulated sugar
  • 1 cup heavy cream

Chocolate Ganache

  • 100 g bittersweet chocolate finely chopped
  • 1/3 cup heavy whipping cream
  • 1 tbsp Kahlua

Topping

  • Cocoa powder for dusting

Instructions

For Chocolate Sponge

  • Preheat oven to 325°F. Line an ungreased 8-inch Cake Pan with parchment paper.
  • In a bowl, sift together the flour, cocoa powder (I use Droste) and salt.
  • In a stand mixer, whip the eggs with the sugar until pale and when you pull the whip out of the foam it creates a ribbon that sits on the surface for a couple of seconds before blending in. Mix the flour into the egg foam, using the whip (I do this by hand, as you'll see in my instagram video) on low speed.
  • In a small bowl, put about 1/3 a cup of the batter. Mix in the oil and vanilla to the small bowl of batter. Fold that mixture into the large amount of batter.
  • Pour the batter into the prepared pan and smooth out the top. Bake for about 20-25 minutes or until a tester comes out clean.
  • Remove from oven, allow to cool in the pan for 10 minutes, then run a knife around the edge of the pan, remove the cake from the pan and cool complete.
  • Once the cake was cool, I cut the cake in half, so I had two disks of cake, because I wanted a smaller ratio of cake to mousse. Fanny used the whole cake.

For Coffee Soak

  • Mix together 2 tablespoons BREWED coffee and 2 tablespoons simple syrup. To make your own simple syrup, bring 1/4 cup sugar and 1/4 cup water to a simmer and cook until sugar is dissolved.
  • Fit the cake into an 8-inch springform cake pan. I used Acetate Clear Cake Strips to make it easier to remove from the pan. Brush the top of the cake lightly with the coffee soak.

For Chocolate Mousse

  • Combine the dark chocolate, butter and coffee in a bowl set over a pan of simmering water, to make a double boiler. Turn off the heat and gently stir until smooth. Allow to cool slightly.
  • In a stand mixer, whip the egg whites until foamy. Add the sugar and continue whipping until the whites are medium peaks form (see my meringue video on instagram for a diagram of medium peaks). Transfer to another bowl.
  • Using the same bowl, whip the egg yolks until pale and fluffy, about 3 minutes. Slowly add the chocolate mixture.
  • Fold the whites into the chocolate mixture in 3 additions.
  • Whip the heavy whipping cream to soft peaks. Fold the cream into the chocolate mixture.
  • Pour the mousse over the cake in the springform pan. Shimmy the pan to make sure the mousse settles flat in the pan. Allow to set for several hours or overnight.

For Ganache

  • Heat the cream and Kahlua in a pan, turn off the heat and add the dark chocolate. Swirl the pan so the chocolate is submerged and allow to sit for 3 minutes. Gently stir until smooth. Pour the mixture over the cake. Refrigerate for at least 10 minutes, but you can do this a day ahead.