200g unsalted butter, room temperature
255g caster sugar
125g muscovado sugar
1 medium egg1 tsp vanilla extract
45g cocoa powder
255g plain flour
¾ tsp bicarbonate of soda
2 tbsp milk
55g plain chocolate chips
55g milk chocolate chips
55g white chocolate chips
Preheat the oven to 180oC/160oC fan oven/350oF/Gas 3.
Line a large baking sheet with greaseproof paper.
Cream the butter and both sugars together, beating until pale and fluffy. Add the egg and the vanilla extract. Once they are mixed, sift in the cocoa powder, flour and bicarbonate. The mixture will now seem a little dry, so add the milk and stir until all ingredients are combined. Stir in the chocolate pieces, but take care you don't over-mix at this stage.
Drop tablespoons of mixture onto the baking sheet, placing each spoonful about 2in apart. If you want to make sure the cookies turn out as neat rounds, pop them in the fridge for half an hour or so before baking. Bake in the preheated oven for 12 minutes.
Let them cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.