250g dark chocolate
1 tsp vanilla essence
60g plain flour
100g dark chocolate, roughly chopped
100g white chocolate, roughly chopped
1. Melt 250g dark chocolate in a heatproof bowl over a pan of simmering hot water. Add in butter once most of the dark chocolate has melted. Stir to ensure even heating. Once the mixture has melted, take off the heat and gradually add sugar.
2. Ensure that the mixture is just warm before cracking in the eggs. Stir well before adding the vanilla essence.
3. Fold the mixture into the flour and add half of the roughly chopped chocolate bits into it. Pour into a baking tin and top it with the remaining bits of roughly chopped chocolate
4. Bake at 150C for 40 minutes. Allow to cool in the oven overnight before serving.