Cut butter into pieces. Mix butter, flour, vanilla sugar, sugar, almonds and egg first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Wrap the dough in foil and chill for about 30 minutes. Roll out dough on a floured work surface approx. 3 mm thin and cut out mushrooms (approx. 4 x 6 cm). Knead dough sections again, roll out and cut out. Spread the cookies on 2-3 baking trays lined with baking paper and bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) one after the other for approx. 8 minutes.
Let the cookies cool down. Sift icing sugar into a bowl. Mix icing sugar and juice to a thick glaze. Halve the icing and color one half red. Brush the mushrooms with the icing and let them dry for about 30 minutes
1 1/4 hours waiting time