01 -
Set your oven to 160°C (320°F) with fan or 170°C (338°F) conventional. Line a baking tray with parchment paper.
02 -
Combine chopped dark chocolate and butter in a heatproof bowl over simmering water, ensuring the bowl doesn't touch the water. Stir occasionally until fully melted. Add vanilla extract and stir to incorporate.
03 -
In a medium bowl, use an electric hand whisk on high speed to beat caster sugar, demerara sugar, and eggs until the mixture becomes light, thick, and fluffy.
04 -
Sift together flour, cocoa powder, baking powder, and salt in a separate bowl to ensure even distribution and no lumps.
05 -
Gradually fold the melted chocolate mixture into the whipped eggs and sugars using gentle strokes to maintain airiness.
06 -
Gently fold the dry ingredients and chocolate chips into the wet mixture with a spatula until just combined. Avoid overmixing to keep the batter light and airy.
07 -
Drop tablespoons of batter onto the prepared baking tray, spacing them well apart to allow for spreading. Bake for 12-14 minutes until set with a crackly top.
08 -
Remove from oven and immediately sprinkle with sea salt if desired. Allow to cool on the baking tray for 10 minutes before transferring to a cooling rack to cool completely.