Preheat your oven to 160°C (320°F) for fan or 170°C (338°F) for conventional. Line a baking tray with parchment paper.

Melt dark chocolate and butter in a heatproof bowl over simmering water, stirring until smooth.

Whisk together caster sugar, demerara sugar, and eggs in a separate bowl until light and fluffy, about 5 minutes.

Sift together flour, cocoa powder, baking powder, and salt in another bowl and stir in chocolate chips.

Fold the melted chocolate mixture into the egg and sugar blend until combined.

Gently fold the dry mixture into the wet mixture until just combined.

Drop rounded tablespoons of batter onto the prepared baking tray, spacing them 2 inches apart.

Bake for 12-14 minutes until edges are crackly and center has a slight jiggle.

Let brookies cool on the tray for 10 minutes, then transfer to a wire rack to cool completely.