Preheat your oven to 160°C (320°F) with a fan or 170°C (338°F) for conventional settings.

In a heatproof bowl, combine dark chocolate and butter, then melt over simmering water for about 5 minutes.

In a large mix bowl, beat eggs and sugars on high speed for about 5 minutes until pale and fluffy.

Sift together flour, cocoa powder, baking powder, and salt in a separate bowl. Add chocolate chips.

Fold the melted chocolate mixture into the whipped egg and sugar mixture.

Gradually fold in the dry ingredient mixture until just incorporated.

Scoop portions of dough onto a prepared baking tray, leaving space for spreading.

Bake for 12-14 minutes until edges are set and tops crackly.

Cool on tray for 10 minutes before transferring to a wire rack to cool completely.