Ingredients
Method
- Step 1: Preheat the oven to 350°F (175°C). Grease two 9-inch round cake pans and line the bottoms with parchment paper.
- Step 2: In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt until evenly mixed.
- Step 3: In a separate bowl, combine milk, eggs, sour cream, vegetable oil, espresso powder, and vanilla extract. Whisk well until smooth.
- Step 4: Gradually add the wet ingredients to the dry ingredients, mixing until just combined. Slowly stir in the hot water until the batter is smooth and thin.
- Step 5: Divide the batter evenly between the pans and bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean. Cool for 10 minutes, then transfer to wire racks to cool completely.
- Step 6: Heat 1 cup of heavy cream in a saucepan until it just begins to simmer. Remove from heat immediately.
- Step 7: In a bowl, whisk egg yolks with sugar and cornstarch until pale and thick. Slowly pour in the hot cream while whisking constantly.
- Step 8: Return the mixture to the saucepan and cook over medium heat, stirring until thickened (about 2–3 minutes). Divide evenly between two bowls.
- Step 9: Add dark chocolate to one bowl and white chocolate to the other, stirring until melted and smooth. Beat the remaining 1 cup of heavy cream to soft peaks and fold half into each mixture.
- Step 10: Place one cake layer on a serving plate. Spread the dark chocolate mousse evenly over it, then top with the second cake layer.
- Step 11: Spread the white chocolate mousse over the top and refrigerate for at least 2 hours to set.
- Step 12: Heat the cream until it begins to simmer, then pour over the chopped milk chocolate. Let sit for 2 minutes and stir until smooth and glossy.
- Step 13: Pour the ganache over the chilled cake, letting it drip down the sides for a tuxedo-like finish. Chill for another 30 minutes before serving.
Notes
For best results, prepare the cake layers a day in advance and refrigerate before assembling. You can also decorate the top with chocolate curls or shavings for an elegant presentation.
