- 185 g unsalted butter
- 185 g best dark chocolate (for melting)
- 85 g plain flour
- 40 g cocoa powder
- 50 g dark chocolate (chunks)
- 50 g white chocolate (chunks)
- 3 large eggs
- 275 g golden caster sugar
Preparation time 10mins
Cooking time 35mins
Adapted from bbcgoodfood.com
Begin preheating the oven to 180°C and line a shallow 20cm square tin with non-stick baking parchment.
Cut the butter into smallish cubes and tip into a medium bowl. Break the dark chocolate into small pieces and drop into the bowl. Fill a small saucepan about a quarter full with hot water, then sit the bowl on top so it rests on the rim of the pan, not touching the water. Put over a low heat until the butter and chocolate have melted, stirring occasionally to mix them.
(Alternatively, cover the bowl loosely with cling film and put in the microwave for 2 minutes on High)
Leave the melted mixture to cool to room temperature.
Sift together the flour and cocoa power into a medium bowl, then chop the white and dark chocolate into chunks on a board.
Break the eggs into a large bowl and tip in the sugar. With an electric mixer on maximum speed, whisk the eggs and sugar until they look thick and creamy, like a milk shake. The mixture is ready when it becomes really pale and about double its original volume. Alternatively, turn off the mixer, lift out the beaters and wiggle them from side to side, looking for a trail.
Pour the cooled chocolate mixture over the eggy mousse, then gently fold together with a rubber spatula. Hold the sieve over the bowl of eggy chocolate mixture and resift the cocoa and flour mixture, shaking the sieve from side to side, to cover the top evenly. Gently fold in this powder before stirring in the white and milk chocolate chunks.
Pour the mixture into the prepared tin, gently easing the mixture into the corners of the tin and paddling the spatula from side to side across the top to level it.
Put in the oven for 25 minutes.
To check for readiness, gently shake the tin. If the brownie wobbles in the middle, it's not quite done, so slide it back in and bake for another 5 minutes. The top should have a shiny, papery crust and the sides just beginning to come away from the tin.
Remove from the oven and leave to cool, then cut and serve.