Mix the quark, sugar, oil, milk, flour, baking powder, egg yolk, lemon flavor and vanilla sugar with a hand mixer. Let the dough rest for two hours. Then form small balls (approx. 35 g) and place 12 pieces on a baking sheet with baking paper. Leave space as the cookies will still get a little more volume. Bake in a preheated oven at 180 ° C for about 20 minutes until they turn golden yellow. Let cool on a wire rack.
Mix the egg white and powdered sugar well and brush onto the biscuits with a brush. Let dry well.
Makes about 70 pieces. They can also be kept well in a suitable can.