in the oven and bake for 18-20 minutes.let the cakes cool slightly before removing from the tin, then leave on a wire rack to cool.
combine the icing sugar with the cocoa powder. whisk this with the butter until you have a fine texture. next, add the milk and gradually increase the speed of the whisk until fluffy and soft. when the cupcakes have cooled, add your icing using a piping bag to create a swirly effect and top with sprinkles! 