Preheat the oven to 180 °C/160 °C fan/gas mark 4 and line a 12 hole muffin tin with paper muffin cases.

Sift the flour, cocoa and baking powder into a bowl. Very roughly chop the Cadbury Giant Buttons into quarters and add to the flour with the sugar.

Mix together the eggs, milk and melted butter and pour on to the dry ingredients. Stir until mixed and a firm batter has formed. Lightly stir in the blueberries.

Divide the mixture equally between the muffin cases. Immediately bake for 20-25 minutes or until well risen and just cooked in the middle.