2½cupsconfectioners' sugar(measured sifted not packed)
½cupespresso coffee(or strong brewed coffee)
1½cupswhipping cream
Garnish
2tablespoonsunsweetened cocoa powder(sifted for top of cake)
whipped cream on top.
2Tablespoonsshaved chocolate curls(on top)
Instructions
Cake
Preheat the oven to 350 ° Grease and flour three 9-inch round pans.
In a mixing bowl beat your cake mix, water, egg whites, and oil in a large bowl with an electric mixer on medium speed until well combined, about 2 minutes.
Divide 2/3 of the batter between 2 prepared pans.
Stir 1 teaspoon instant coffee powder into one tablespoon of water dissolving the granules and add it to the last 1/3 remaining batter and mix until combined, pour that into the last remaining prepared pan.
Bake cakes in the preheated oven until a toothpick inserted into the center of cakes comes out clean, 23 to 28 minutes.
Cool cakes in the pans for 10 minutes, then turn out onto a wire rack to cool completely.
Filling and Frosting
Make sure mascarpone cheese, coffee and cream are very cold.
Beat mascarpone on medium speed for about 2 minutes until it is creamy. Add the confectioners' sugar, and espresso coffee and continue to beat on medium until combined and creamy. Stir in the whipping cream and mix it on medium speed for another 2-3 minutes until creamy. Place covered in the refrigerator to keep cool if the cakes are not ready yet.
Assembling the cake
On a cake plate or cake stand place one layer of the white cake. Brush the cake with the espresso coffee using about 1/3 of the coffee.
Then spread 1/3 of the mascarpone cream on top of that cake layer. Repeat this with one more layer using the dark cake. So the dark cake is in the middle layer of the cake.
Place the last layer of white cake on top, using the last of the coffee brush the cake. Using the last 1/3 of mascarpone cream, lightly frost the outside and the sides of the cake.
Chill cake in the refrigerator for at least 2 hours before serving to let the flavors incorporate well.
Garnish your cake right before serving: Pipe whipped cream on top if desired. Place cocoa powder in a sieve and lightly dust the top of cake. Run a vegetable peeler down the edge of chocolate square to form curls. Scatter chocolate shavings over cake.