Tiramisu-Inspired Layer Cake

Directions

1. Prepare boxed cake mix according to instructions on box. Bake according to box directions for either two 8" or 9" round pans. Cool cakes completely in pans (you can speed this process up by placing the pan directly from the oven into the freezer for about 10 minutes, then leave at room temperature until ready to assemble).
2. While cake is baking, prepare the coffee syrup and mascarpone frosting.
3. Coffee syrup: In a medium saucepan over medium-low heat, add the brewed coffee (or 2c water and 1 1/2 tbsp high-quality instant coffee powder) and the granulated sugar. Stir until the sugar is completely dissolved then remove from heat to cool until ready to use.
4. Mascarpone Frosting: Using a hand-mixer in a high-side mixing bowl, whip the mascarpone on medium until slightly softened (it will still look a bit chunky and not completely smooth - that's okay!). Add the heavy whipping cream and whip at medium-high speed until well-blended and slightly lightened in color (about 2-5 minutes). Add the light corn syrup and whip about 2-3 more minutes. Add the powdered sugar in to batches and mix until completed blended after each addition. The frosting is meant to be only slightly sweet and will look spreadable but a little lumpy. You may adjust sweetness by adding more powdered sugar, a tbsp at a time, if desired.
5. Once all the cakes are cooled completely and the syrup and frosting are made, it's time to assemble! If you want very even layers, slice the rounded tops off of the cakes. If you don't mind a bit of a "bubble" on your finished cake, your can just stack the cakes as they are (like I did!)
6. Place a dab of frosting on the surface of the decorating plate (to keep the bottom cake layer from sliding around). Place one layer of cake on the decorating plate.
7. Pour the coffee syrup into a spouted squeeze bottle. You will likely have extra coffee syrup leftover (or if you really enjoy the coffee flavor of tiramisu, feel free to use it all!
8. If you sliced your cake tops off, liberally squeeze the coffee syrup over the cake. Leave it for a few minutes to soak in. You may want to do this one or two more times, depending on how well the syrup is absorbed into the cake (you want it soaked, but not leaking out of the bottom of the cake layer). If you did not cut your cake tops, use a dinner fork to poke lots of holes in the top of the cake, then squeeze coffee syrup liberally over the cake. Leave it for a few minutes to soak in. You may want to do this one or two more times, depending on how well the syrup is absorbed into the cake (you want it soaked, but not leaking out of the bottom of the cake layer).
9. Cover the cake top with about 1/4 of an inch of frosting. Don't do the sides yet - those will get done with the top layer! Sift about half of the cocoa powder on top of the frosting - be very liberal - you don't want to see any frosting through the cocoa powder.
10. Place the second cake layer on top of the first and repeat steps 7 and 8 to soak the cake layer with coffee syrup. Frost just the top of the cake with about 1/4 - 1/2 inch of frosting (depending one your tastes). Frost the sides and edges, using an off-set spatula, until you have about 1/3 - 1/2 inch coat of icing all around the cake.
11. Liberally sift the remaining cocoa powder over the top of the cake - you don't want to see any frosting on the top! If some cocoa gets on the sides, that's great! You may even want to dust the sides, if you want.