Brownie Recipe

Preheat and prepare pan

Preheat oven to 350°F (175°C). Line a 4x4-inch or similarly small square baking pan (or an oven-safe ramekin for a single brownie) with parchment paper leaving an overhang for easy removal, or lightly grease the pan.

Melt chocolate and butter

Combine the chopped bittersweet chocolate and unsalted butter in a heatproof bowl. Melt together using a microwave in 20- to 15-second bursts, stirring between each until smooth, or place the bowl over a saucepan of simmering water (double boiler) and stir until fully melted. Remove from heat and let cool slightly, about 3 minutes.

Combine sugars and egg

Whisk granulated sugar and light brown sugar into the warm chocolate-butter mixture until combined. Add the large egg and vanilla extract and whisk vigorously for about 30 seconds until mixture is glossy and slightly thickened. This step helps build structure and shine in the brownie.

Add dry ingredients

Sift or whisk together the all-purpose flour, unsweetened cocoa powder, and fine sea salt in a small bowl. Fold the dry ingredients into the chocolate mixture using a rubber spatula just until no streaks of flour remain. Do not overmix to keep the brownie fudgy.

Fold in mix-ins

If using optional chopped walnuts or chocolate chips, fold them into the batter now, keeping a few teaspoons to sprinkle on top if desired.

Transfer to pan

Scrape the batter into the prepared pan or ramekin and smooth the top. Sprinkle the reserved mix-ins on top if you set any aside.

Bake

Bake in the preheated oven for 18–24 minutes for a 4x4-inch pan, or 20–26 minutes for a deeper ramekin. Begin checking at 18 minutes: the edges should be set and a thin crust formed on top; a toothpick inserted into the center should come out with a few moist crumbs but not raw batter. Baking time will vary with oven and pan depth.

Cool

Remove from oven and place on a wire rack. Let the brownie cool in the pan for at least 30 minutes (longer if using a thicker ramekin) to firm up and make slicing easier. Use the parchment overhang to lift the brownie from the pan if used.

Serve

Dust the top lightly with powdered sugar if desired. Cut into one generous square (or serve the single ramekin portion as-is). Serve at room temperature or slightly warm (reheat briefly in the microwave for 8–12 seconds if desired).