Ingredients

For the Cake Base:
– 1 cup all-purpose flour
– 1/2 cup unsweetened cocoa powder
– 1 cup granulated sugar
– 1/2 teaspoon baking powder
– 1/2 teaspoon baking soda
– 1/4 teaspoon salt
– 1/2 cup unsalted butter, room temperature
– 2 large eggs
– 1/2 cup whole milk
– 1/2 cup boiling water
– 1 teaspoon vanilla extract

For the Chocolate Mousse:
– 8 oz (1 cup) semi-sweet chocolate, chopped
– 1 cup heavy cream
– 3 large eggs, separated
– 1/4 cup granulated sugar
– 1 teaspoon vanilla extract
– Pinch of salt

For the Ganache:
– 1 cup semi-sweet chocolate, chopped
– 1/2 cup heavy cream

For Garnish (optional):
– Whipped cream
– Shaved chocolate or cocoa powder

  Instructions

1. Preheat Oven:
– Preheat your oven to 350°F (175°C). Grease and flour an 8-inch round cake pan, or line the bottom with parchment paper.

2. Prepare the Cake Base:
– In a medium bowl, sift together the flour, cocoa powder, sugar, baking powder, baking soda, and salt.
– In a large bowl, beat the butter until creamy.
– Add the eggs one at a time, beating well after each addition.
– Mix in the milk and vanilla extract.
– Gradually add the dry ingredients, mixing until just combined.
– Stir in the boiling water until the batter is smooth (it will be thin).
– Pour the batter into the prepared cake pan and bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
– Let the cake cool completely in the pan on a wire rack before removing.

3. Prepare the Chocolate Mousse:
– Melt the chocolate in a heatproof bowl over a pot of simmering water (double boiler) or in the microwave in 30-second intervals, stirring until smooth. Let it cool slightly.
– In a medium bowl, beat the heavy cream until soft peaks form.
– In another bowl, beat the egg yolks and sugar until pale and thick.
– Mix the melted chocolate into the egg yolk mixture until well combined.
– Fold in the whipped cream gently until the mousse is smooth and well combined.
– In a separate bowl, beat the egg whites with a pinch of salt until stiff peaks form.
– Fold the beaten egg whites into the mousse mixture gently until no streaks remain.

4. Assemble the Cake:
– Place the cooled cake base on a serving plate or a cake board.
– Spread a layer of chocolate mousse over the cake, smoothing it out with a spatula.
– Refrigerate the cake for at least 2 hours to let the mousse set.

5. Prepare the Ganache:
– Heat the heavy cream in a small saucepan over medium heat until it just begins to simmer.
– Pour the hot cream over the chopped chocolate in a heatproof bowl.
– Let it sit for 2-3 minutes, then stir until smooth and glossy.
– Allow the ganache to cool slightly before pouring it over the set mousse.

6. Finish and Garnish:
– Pour the ganache over the chilled mousse layer, spreading it evenly.
– Refrigerate the cake for at least another hour, or until the ganache is set.
– Garnish with whipped cream and shaved chocolate or a dusting of cocoa powder if desired.

Serve this Chocolate Mousse Cake chilled and enjoy the creamy, chocolatey indulgence!