Grind the almonds very finely in a universal chopper. Pass 250 g icing sugar through a sieve. Beat 3 egg whites with the whisks of the hand mixer until very stiff. Add sifted icing sugar by the spoonful and stir in.
To brush the stars, put 5-6 tablespoons of beaten egg white aside. Stir almonds, vanilla sugar, cinnamon and bitter almond oil into the remaining beaten egg white. Roll out the dough on a work surface sprinkled with icing sugar to a thickness of approx. 1/2 cm and cut out stars (approx. 5 cm Ø).
Place the stars on two baking trays lined with baking paper, brush them carefully with the beaten egg white put aside and bake in the preheated oven (electric oven: 150 °C/ gas: level 1-2) for 18-20 minutes in succession.
Let cinnamon stars cool down on a cake rack. In the meantime, mix the remaining icing sugar and egg white with the whisk of the hand mixer to a creamy mixture. Pour the icing sugar icing into three bowls and colour each with a few drops of food colouring.
Fill each glaze into a small freezer bag, cut off a small corner with scissors and decorate the cinnamon stars with it as desired. Let the icing dry.