01 -
Preheat oven to 350°F. Coat two 9-inch round pans with a baking spray.
02 -
Combine cake mix, water, oil, and egg whites and stir until lump-free.
03 -
Pour batter into pans. Bake for 22-25 mins, or until a toothpick comes out clean. Let the cakes cool fully.
04 -
Stir together the hot water, espresso powder, sugar, and Kahlua. Put it aside for later.
05 -
In a bowl, stir mascarpone until the texture is creamy.
06 -
Whisk cold heavy cream and vanilla extract until stiff peaks form. It should take about 3-5 minutes.
07 -
Slowly sprinkle sugar into whipped cream as you continue beating it for 1-2 extra minutes.
08 -
Gently fold mascarpone into the whipped cream in small portions, a quarter at a time.
09 -
Put ⅔ cup frosting into a piping bag fitted with a star tip, then set it aside.
10 -
Using a serrated knife, cut each cake in half horizontally to make 4 thin layers.
11 -
Start with one cake layer on a plate. Brush coffee syrup over it and top with 1¼ cups of frosting. Repeat for the next two layers.
12 -
Spread coffee syrup onto the last layer, then smooth 1½ cups of frosting on top.
13 -
Use the leftover frosting to coat the sides of the cake.
14 -
Gently dust cocoa powder over the top with a sifter.
15 -
Pipe frosting swirls around the edge and middle, then finish with a coffee bean on each swirl.