Tiramisu Layer Cake

1. Stage

Preheat the oven to 350 degrees F (175 degrees C). Grease and flour three 9-inch pans.

2. Stage

Make cake: Beat 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 instant coffee into remaining batter; pour into the remaining prepared pan.

3. Stage

Bake 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.

4. Stage

Make syrup: Combine brewed coffee and coffee liqueur in a measuring cup; set aside.

5. Stage

Make filling: Beat mascarpone, confectioners' sugar, and coffee liqueur in a medium bowl with an electric mixer on low speed until smooth. Cover with plastic wrap and place in the refrigerator to keep cool.

6. Stage

Make frosting: Beat cream, confectioners' sugar, and coffee liqueur in a medium bowl with an electric mixer on medium-high speed until stiff. Fold 1/2 cup frosting into chilled filling until combined. Store frosting and filling, covered, in the refrigerator to keep cool.

7. Stage

Assemble cake: Place 1 plain cake layer on a serving plate. Using a thin skewer, poke holes in cake, about 1 inch apart. Pour 1/3 of the coffee syrup over cake, then cover with 1/2 of the filling. Top with coffee-flavored cake layer; poke holes in cake. Pour another 1/3 of the coffee syrup over cake and cover with remaining filling. Top with remaining cake layer; poke holes in cake. Pour remaining coffee syrup on top. Spread sides and top of cake with frosting.

8. Stage

Garnish cake: Place cocoa powder in a sieve and lightly dust top of cake. Run a vegetable peeler down the edge of chocolate square to form curls. Scatter chocolate curls over cake.

9. Stage

Chill cake in the refrigerator for at least 30 minutes before serving. Kim