Preheat Oven: Heat oven to 350°F (175°C). Line an 8x8-inch (20cm) baking pan with parchment paper.
Make Brownie Batter: In a bowl, whisk together melted butter, sugar, and vanilla. Beat in eggs one at a time. Sift in cocoa powder, flour, and salt. Stir until combined.
Bake Brownies: Pour batter into prepared pan and bake for 30–35 minutes, or until a toothpick comes out with moist crumbs. Let cool completely.
Prepare Mascarpone Cream: In a mixing bowl, whip mascarpone, cream, powdered sugar, and vanilla until smooth and fluffy.
Add Coffee Flavor: Brush cooled brownies with espresso to soak slightly without making them soggy.
Layer Tiramisu Cream: Spread the mascarpone mixture evenly over brownies. Dust generously with cocoa powder.
Chill and Slice: Refrigerate for at least 1 hour before slicing into squares for clean edges.