01 -
Preheat oven to 160°C (fan 150°C). Line a 23 cm x 23 cm square baking pan with baking parchment or greaseproof paper.
02 -
Combine the butter and dark chocolate in a heatproof bowl. Melt over a simmering pan of water, or heat in the microwave at medium power in 30-second intervals, stirring between each session, until smooth and fully melted.
03 -
Place eggs and granulated sugar in the bowl of an electric mixer fitted with a whisk attachment. Beat on high speed until mixture is pale and fluffy. An electric hand whisk can also be used.
04 -
Gently pour melted chocolate and butter mixture into the whipped eggs and sugar. Use a hand whisk to carefully fold until just combined.
05 -
Sieve the cocoa powder and flour together over the batter. Gently fold the dry ingredients in, mixing until just incorporated. Do not over-mix.
06 -
Pour the prepared batter into the lined baking tin. Bake in the preheated oven for 15 minutes, turn the pan, then continue baking for an additional 10–15 minutes. The brownies are done when the top is shiny, crackly, and set. Avoid overbaking.
07 -
Remove from the oven and allow brownies to cool in the tin for at least 1 hour. Slice into squares using a hot, dry knife, wiping clean between each cut for neat edges.