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

In a heatproof bowl, combine dark chocolate and butter over simmering water. Stir until smooth and glossy, then remove from heat and stir in vanilla extract.

In a separate bowl, whisk together eggs and both sugars on high speed for about 5 minutes until light and fluffy.

Sift together plain flour, cocoa powder, baking powder, and salt. Fold in chocolate chips.

Fold the cooled chocolate mixture into the egg and sugar blend carefully to retain airiness.

Gradually fold sifted dry ingredients into the wet mixture until just combined.

Drop dollops of dough onto prepared tray, spacing them about 2 inches apart. Bake for 12-14 minutes until edges begin to set.

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