Preheat your oven to 175°C (350°F) and line your baking pan with parchment paper, leaving overhang for easy removal.
Chop the dark chocolate into small pieces and melt it together with the softened butter in a heatproof bowl over simmering water, stirring until glossy and smooth.
Whisk the eggs and granulated sugar in a large bowl until the mixture is pale, thick, and slightly fluffy, about 2 minutes. Add vanilla extract and mix again.
Pour the warm chocolate-butter mixture into the egg mixture, folding gently with a spatula until completely combined and shiny.
Sift the flour, cocoa powder, and salt into the batter, then fold carefully just until no streaks remain. Be gentle to keep the batter airy.
Pour the batter into the prepared pan and smooth the top with a spatula. Tap the pan lightly on the counter to eliminate air bubbles.
Bake for 20–25 minutes, until the edges are set and a toothpick inserted into the center comes out with moist crumbs. The top should be crackly and shiny.
Remove the pan from the oven and let the brownies cool in the pan for 15 minutes before transferring to a wire rack to cool completely.
Once cooled, lift the brownies out using the parchment overhang and cut into squares with a sharp knife. Wipe the knife clean between cuts for neat slices.
Serve the brownies at room temperature or slightly warmed for a gooey, fudgy experience. Enjoy the rich, chocolatey aroma and silky texture with every bite.
