Mix powdered sugar with the butter and stir until a fluffy cream. To this mixture add pre-beaten egg with vanilla, essence and grated orange peel. Mix until a homogenous mixture. Then begin adding the flour gradually until we get very soft dough, which is sprayed on baking paper. Bake in a preheated oven 190C degrees (fan) until the turn pink. You can sprinkle them with powdered sugar.