Preheat your oven to 180°C (350°F) and line an 8-inch square baking pan with parchment paper.
In a heatproof bowl, melt the dark chocolate, milk chocolate, and butter together until smooth.
Whisk in both sugars while the mixture is still warm — it gives the brownies that shiny, crackly top.
Add the eggs one at a time, followed by the vanilla extract. Stir until glossy and thick.
Sift in the flour, cocoa powder, and salt, then fold gently. Don’t overmix — a few streaks are fine.
Stir in the white chocolate chips for that surprise bite of sweetness.
Pour the batter into the prepared pan, smoothing the top evenly.
Bake for 25–30 minutes or until the center is just set. The toothpick should come out with moist crumbs.
Let them cool before slicing (or don’t, I won’t judge). Cut into squares and enjoy warm or chilled.