INGREDIENTS

Makes 16 squares

• 185g unsalted butter
• 185g best dark chocolate
• 85g plain flour
• 40g cocoa powder
• 50g white chocolate
• 50g milk chocolate
• 3 large eggs
• 275g golden caster sugar

METHOD

1. Cut 185g unsalted butter into small cubes and tip into a medium bowl, along with 185g of dark chocolate, broken into pieces.
2. Melt the chocolate and butter over a bain marie. Once melted, remove and set aside.
3. While chocolate cools, preheat the oven to 180C.
4. Line a shallow 20cm square tin with non-stick baking parchment.
5. Add 85g plain flour and 40g cocoa powder into a sieve and shake into a medium bowl.
6. Chop 50g white chocolate and 50g milk chocolate into chunks and set aside.
7. Using an electric whisk, whisk together 3 large eggs and 275g golden caster sugar – they will look thick and creamy. This can take 3-8 minutes, depending on how powerful your mixer is. You’ll know it’s ready when the mixture becomes really pale and about double its original volume. 
8. Pour the cooled chocolate mixture over the eggy mousse, then gently fold together with a rubber spatula until the two mixtures are one.
9. 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.
10. Gently fold in this powder to a fudgy consistency.
11. Stir in the white and milk chocolate chunks.
12. Pour the mixture into the prepared tin (add your toppings now if you want to bake them into the mixture)
13. Bake in the oven for 25 mins – when it’s done the edges should be crusty and the top shiny.
14. Leave to cool in the tin.
15. Once cool, remove and cut into squares.
16. Decorate as you wish!