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

In a heatproof bowl, combine butter and semisweet chocolate over simmering water until melted and smooth.

Remove from heat, then stir in the granulated sugar until well blended.

Beat in each egg one at a time. Add the vanilla extract and mix until combined.

In a separate bowl, sift together flour, cocoa powder, and salt. Gently fold this into the chocolate mixture using a spatula.

Pour the batter into the prepared pan and bake for 20-25 minutes, or until a toothpick inserted comes out with moist crumbs.

Allow the brownies to cool completely on a wire rack before cutting them into squares.

Melt the additional chocolate for dipping and carefully dip each brownie halfway. Set them aside to allow the chocolate to firm up.