Beat the egg whites until stiff. Gradually sift in powdered sugar. Beat for at least 7 minutes until the mixture is glossy. Cover and set aside 3 tablespoons of this for the cookie glaze. Carefully fold the cinnamon powder, lemon juice (or kirsch) and almonds into the egg whites. Shape the mixture into a ball and cover and chill for 1 hour. Roll out the dough on sugar (or between foil) about 1/2 cm thick. Cut out stars and place on a baking tray lined with baking paper. Brush each star with the egg white glaze. The best way to do this is with a fine brush. Pull out the tips with a knitting needle. If possible, let the cinnamon star dry overnight at room temperature. When baking, the glaze should stay light.