Preheat the oven to 180°C fan / 200°C conventional and generously grease a 12-hole cupcake tray with butter.
Finely chop the dark chocolate and place in a microwave-safe bowl. Add the butter. Microwave for 60 seconds or until fully melted. Stir to combine, then set aside and leave to cool.
150 grams 70% dark chocolate , 150 grams Unsalted butter
Meanwhile, whisk the sugar and eggs together for 1-2 minutes until thick, pale in colour and foamy. If you lift the whisk up, the mixture should fall off the whisk in a ribbon-like continuous stream.
220 grams Caster sugar, 2 Eggs
Whisk the flour and cocoa powder together until well combined.
130 grams Self raising flour, 20 grams Cocoa powder
Pour the chocolate mixture into the whisked eggs. Add the dry ingredients. Fold the mixture together in a figure-of-eight motion until just combined.
Use a cookie scoop or spoon to fill each hole of the baking tin with brownie mixture. Bake for 12-14 minutes.
Remove the brownies from the oven and immediately use a scoop, the back of a spoon, or the base of a small jar to press the brownies into a cup shape.
Refrigerate for 2 hours, or until cool and set.