Creating Tiramisu Brownies can be broken down into clear, manageable steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease and line a 9×13-inch baking pan with parchment paper.
2. Melt Butter: In a medium saucepan over low heat, melt the unsalted butter. Remove from heat.
3. Add Sugars: Stir in granulated sugar and brown sugar until well combined.
4. Add Eggs: Once slightly cooled, whisk in eggs one at a time, followed by the vanilla extract until smooth.
5. Mix Dry Ingredients: In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt.
6. Combine Mixtures: Gradually fold the dry mixture into the wet mixture until just combined. Do not overmix.
7. Add Coffee: Stir in the brewed coffee, ensuring an even consistency.
8. Bake Brownies: Pour the brownie batter into the prepared baking pan, spreading evenly. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
9. Cool Completely: Let the brownies cool in the pan for 20 minutes, then transfer to a wire rack to cool completely.
10. Make the Mascarpone Layer: In a mixing bowl, combine mascarpone cheese, heavy cream, and powdered sugar. Beat until soft peaks form.
11. Layer: Once brownies are cooled, spread the mascarpone mixture evenly over the top.
12. Dust with Cocoa: Lightly dust the top with unsweetened cocoa powder using a fine-mesh sieve.
13. Chill: Cover and refrigerate for at least 1 hour to set before slicing into squares.

By following these straightforward steps, you’ll have delicious Tiramisu Brownies ready to impress.