Ingredients
**Chocolate Cake:**
- – 3/4 cup all-purpose flour
- – 1/2 cup unsweetened cocoa powder
- – 1 cup granulated sugar
- – 1 teaspoon baking soda
- – 1/2 teaspoon baking powder
- – 1/2 teaspoon salt
- – 1/4 cup melted butter
- – 1/2 cup buttermilk
- – 1 egg
- – 1 teaspoon vanilla extract
- – 1/2 cup warm water
**Chocolate Mousse:**
- – 14 ounces dark chocolate (70% cocoa, chopped)
- – 2 tablespoons butter
- – 1/4 cup Kahlua (or brewed coffee)
- – 3 large eggs (separated)
- – 1/4 cup granulated sugar
- – 1 teaspoon unflavored gelatin
- – 3 tablespoons water
- – 1 1/2 cups heavy whipping cream (divided)
**Chocolate Ganache:**
- – 4 ounces dark chocolate (70% cocoa, chopped)
- – 4 tablespoons butter
- – 1/2 teaspoon vanilla extract
- – 1/4 teaspoon kosher salt
- – 1/2 cup heavy whipping cream
Instructions
**Chocolate Cake:**
- Preheat the oven to 350°F.
- Line a 9” springform pan with parchment paper and set aside.
- In a large bowl, whisk together the flour, cocoa powder, sugar, baking soda, baking powder, and salt.
- Add the melted butter, buttermilk, egg, vanilla, and warm water. Mix until combined.
- Pour the batter into the prepared pan.
- Bake for 45 minutes or until a toothpick comes out clean. Let it cool.
**Chocolate Mousse:**
- In a double boiler, melt the chopped dark chocolate, butter, and Kahlua over medium heat. Set aside to cool slightly.
- In a stand mixer, whip the egg whites on medium speed until foamy. Gradually add the sugar and whip until medium peaks form.
- Bloom the gelatin in the water for at least 5 minutes.
- Whip the egg yolks until pale and fold them into the chocolate mixture.
- Warm 1/2 cup of heavy cream and mix in the gelatin. Fold this into the chocolate mixture.
- Fold the whipped egg whites into the chocolate mixture.
- Whip the remaining 1 cup of heavy cream to soft peaks and fold into the chocolate mixture.
- Pour the mousse over the cooled cake in the springform pan. Spread evenly and cover with plastic wrap. Chill for at least 4 hours or overnight.
**Chocolate Ganache:**
- Place the chopped chocolate, butter, vanilla, and salt in a bowl.
- Heat the heavy cream until just before boiling and pour over the chocolate mixture. Let sit for 2 minutes, then stir until smooth.
- Let the ganache cool slightly, then pour over the chilled mousse cake. Chill for about 30 minutes until set.
**Assembly:**
- Run a knife along the edges of the springform pan and remove the outer ring.
- Slice and serve the cake.