Spread the mascarpone cream over the top of the brownies.
Add your cocoa powder to a sifter and shake the cocoa powder over the top of the mascarpone cream.
2 tablespoons unsweetened cocoa powder
Place the brownies in the refrigerator for at least one hour to set the mascarpone layer.
Notes
Semisweet baking chocolate: I like to use a baking bar, like Ghirardelli. You could also use good-quality chocolate chips.
Butter: I use salted butter in this recipe.
Brown sugar: Either light brown sugar or dark brown sugar will work in this recipe.
Espresso powder: You could use a bold, dark instant coffee powder instead. If you'd like to make tiramisu brownies without coffee, you could use hot cocoa powder instead.