Preheat your oven to 350°F (175°C) and grease a 9x9-inch baking pan.

In a heatproof bowl, melt together 8 oz of dark chocolate and ½ cup of butter over simmering water until smooth.

Remove from heat, stir in 1 cup of granulated sugar, and then add 3 eggs one at a time, whisking vigorously until well combined.

Gently fold in ¾ cup of all-purpose flour and 1 tbsp of espresso powder until just mixed without overmixing.

Pour the brownie batter into the greased baking pan, spreading it evenly.

Place the pan in the preheated oven and bake for 30 minutes until the toothpick comes out with moist crumbs.

Allow the brownies to cool completely in the pan on a wire rack.

In a mixing bowl, whisk together 8 oz of mascarpone cheese until smooth and creamy.

Once your brownies are completely cool, gently spread the mascarpone mixture evenly over the top.

Cover the pan with plastic wrap or aluminum foil and place it in the refrigerator. Chill for at least 2 hours.

Dust the top generously with cocoa powder using a fine sieve for a chocolatey finish.

Using a sharp knife warmed under hot water, slice the brownies into squares for a perfect clean cut.

Serve chilled or at room temperature.