The butter and sugar are broken foam. Add the egg yolks one by one, the flour with baking powder, grated peel of one orange. Stir and add the beaten egg white. Pour in shape covered with baking paper. Bake 30 minutes at 180 C. Remove and cake on lining fan cut into thin slices oranges, rolled in sugar. Again bake outer burning oven for 10 minutes. Remove from the mold once cool and spray with plenty of liquor.