Whisk together the eggs and sugar until pale, fluffy and doubled in size. Slowly fold in the flour, cocoa powder and baking powder. Add the almond extract and grated chocolate.
Slowly add the melted butter, gently folding in until combined. Cover and chill in the fridge for at least 30mins.
Preheat the oven to 190° / Gas 5. Grease the madeleine tray and spoon in the mixture. Bake for 7 mins until risen and golden. Leave to cool in the tin for 5 mins, then turn out and cool on a rack.