The Chocoholic
Author: 
Makes: MAKES ONE 8-INCH (20-CM) LAYER CAKE
 
Ingredients
FOR THE CAKE:
  • 2 cups (280 g) all-purpose flour
  • ½ cup (40 g) dark Dutch-process cocoa powder (like Cacao Barry Extra Brute)
  • 1 teaspoon baking powder
  • 1 teaspoon baking soda
  • 1 teaspoon salt
  • ¼ cup (60 ml) hot brewed coffee
  • 4 ounces (115 g) bittersweet chocolate (like Lindt 70%), finely chopped
  • 1 cup (240 ml) buttermilk
  • 1 cup (220 g) light brown sugar, packed
  • 1 cup (200 g) granulated sugar
  • 1 cup (240 ml) canola oil
  • 3 large eggs
  • 1 teaspoon vanilla bean paste
FOR THE CHOCOLATE MOUSSE FILLING:
  • 2 cups (480 ml) cold heavy cream
  • 4 large eggs, separated
  • 2 tablespoons plus ¼ cup (50 g) sugar
  • 1 tablespoon vanilla bean paste
  • 8 ounces (225 g) bittersweet chocolate (at least 70%), finely chopped
  • Pinch of salt
FOR THE GANACHE:
  • 1 pound (455 g) bittersweet chocolate, finely chopped
  • 2 tablespoons unsalted butter
  • 1½ cups (360 ml) heavy cream
  • Pinch of salt
Instructions
  1. MAKE THE CAKE: Preheat the oven to 325°F (165°C). Spray three 8-inch (20-cm) round cake pans with nonstick cooking spray and line the bottoms with a round of parchment paper.
  2. In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt for 30 seconds to evenly distribute the leavening.
  3. In a heat proof bowl, pour the hot coffee over the chopped chocolate and let sit undisturbed for 3 minutes to allow the chocolate to melt. Whisk to combine. Add the buttermilk and stir.
  4. In the bowl of a stand mixer fitted with the whisk attach¬ment, beat both sugars and the oil together until well com¬bined. Add the eggs one at a time, mixing well after each addition. Add the vanilla and mix.
  5. With the mixer running on low speed, add half of the flour mixture, then add half of the buttermilk mixture. Add the remaining flour mixture, then the remaining buttermilk mixture, and mix until smooth and well combined. Divide the batter evenly among the prepared pans and bake until the cake springs back when gently poked, 30 to 40 minutes. Let cool completely.
  6. MAKE THE CHOCOLATE MOUSSE FILLING: Combine 1 cup (240 ml) of the cream, the egg yolks, the 2 tablespoons sugar, and the vanilla in a heatproof bowl and whisk to combine. Place the bowl over a saucepan of sim¬mering water (to make a double boiler) and whisk constantly until the mixture thickens and coats the back of a spoon. Add the chocolate and continue whisking until the choco¬late melts into the mixture. Set aside and let cool to room temperature.
  7. In the clean bowl of a stand mixer fitted with the whisk attachment, combine the egg whites, the remaining ¼ cup (50 g) sugar, and the salt. Place the bowl over a saucepan of simmering water (to make a double boiler) and whisk constantly until the sugar dissolves and the temperature of the mixture reaches 160°F (71°C) on a candy thermometer. Transfer the bowl to the stand mixer and whisk until the meringue forms stiff, very smooth white peaks (don’t whisk so much that they become dry and chunky).
  8. Using a large rubber spatula, carefully fold the egg whites into the room-temperature chocolate mixture until smooth.
  9. In the same bowl you whipped the egg whites, whip the remaining 1 cup (240 ml) cream to stiff peaks. Gently fold the whipped cream into the chocolate mixture with the large rubber spatula. Cover the bowl with plastic wrap and refrig¬erate until the mousse has set, about 1 hour.
  10. Using an offset spatula, spread half the mousse onto a chocolate cake layer. Place a second cake layer atop the mousse filling and spread the remaining mousse over the second cake layer. Place the final layer of cake on top of the mousse filling and cover the cake tightly with plastic wrap. Refrigerate until the mousse has set, at least 2 hours.
  11. MAKE THE GANACHE: Put the chocolate and butter in a large heatproof bowl.
  12. In a large saucepan, bring the cream and salt to a simmer, but do not boil. Pour the cream over the chocolate, making sure that the chocolate is completely covered. Let sit undis¬turbed for 3 minutes, then whisk the mixture until smooth. Cover the bowl with plastic wrap and set aside until the ganache has cooled to room temperature but is still spread¬able, about 45 minutes.
  13. Place the ganache in the bowl of a stand mixer fitted with the whisk attachment and whisk until it lightens and becomes fluffy. Spread the ganache over the top and sides of the assembled cake.
Recipe by Bakepedia at https://www.bakepedia.com/the-chocoholic/