Mix flour, sugar, sour cream and butter with the dough hooks of the hand mixer. Then knead with your hands to a smooth dough. Roll out two millimetres on a floured work surface.
Cut out cookies with shooting stars and moon cutters and place them on a baking tray lined with baking paper. Whisk egg yolk with cream. Spread the biscuits. Sprinkle half with sugar crystals.
Bake in the preheated oven (E:-stove: 200 ° C/ gas: level 3) for about twelve minutes. Let the cookies cool down on a cake rack. Mix icing sugar with two tablespoons of water. Spread the ungarnished biscuits and sprinkle with love beads.