Preheat your oven to 175°C (350°F) and line an 8-inch square baking pan with parchment paper, leaving a slight overhang for easy removal.
Melt the butter and chopped dark chocolate together using a double boiler or microwave in short bursts, stirring until smooth and glossy. Let the mixture cool slightly until it feels warm to the touch.
In a large bowl, whisk the eggs and sugar together until the mixture becomes slightly frothy and light in color, about 1 minute. This helps incorporate air and creates a glossy base.
Pour the slightly cooled chocolate mixture into the egg mixture and stir until fully combined and smooth, releasing a rich chocolate aroma.
Sift the sifted flour, cocoa powder, and a pinch of salt into the wet ingredients. Gently fold the dry ingredients into the wet with a spatula until just combined, being careful not to overmix to keep the brownies fudgy.
Pour the batter into your prepared pan and spread evenly with a spatula, smoothing the top and ensuring each corner is filled.
Bake in the preheated oven for 20-25 minutes. The edges should be firm and slightly pulling away from the pan, while the center remains just set and slightly jiggly.
Remove the pan from the oven and let the brownies cool in the pan on a wire rack for about 15 minutes. This allows the top to crack naturally and develop that shiny, crackly surface.
Once cooled, lift the brownies out using the parchment overhang and transfer to a wire rack for complete cooling. Slice into squares with a sharp knife for clean edges.
Serve the brownies on a plate or store in an airtight container at room temperature for up to 3 days, or freeze for longer storage. Enjoy the dense, fudgy texture with a glass of milk or on its own!
