Melt the dark chocolate and butter together in a saucepan on low heat or in the microwave in short bursts. Stir until smooth, then let it cool for a couple of minutes so the eggs don’t scramble.

In a bowl, whisk the eggs, caster sugar, and Demerara sugar for about 1 minute. The mixture should look slightly thick. This helps create that soft chewy center.

Pour the cooled chocolate mixture into the egg mixture and stir it in with a spatula until everything is combined.

In another bowl, mix the flour, cocoa powder, baking powder, and salt. Add this to the chocolate bowl and fold gently. Try not to overmix so the brookies stay soft.

Fold in the chocolate chips. The dough should look thick and glossy.

Scoop small portions of the dough onto a lined baking tray. Leave enough space because they spread slightly. Bake at 350°F (175°C) for 10–12 minutes. The tops should have light cracks.

Let the brookies cool on the tray for 10 minutes. They set as they cool and turn perfectly chewy.