Stir the quark, milk, oil, salt, sugar, vanillin sugar and grated lemon peel until smooth. Mix flour and baking powder and knead into the quark mixture. Drain the peaches on a sieve.
Separate the egg, mix the egg yolk and cream. Roll out the quark oil dough thinly on a floured work surface. Cut out 4 squares (each approx. 12 x 12 cm) and 4 circles (each approx. 14 cm Ø) (knead the rest of the dough once and roll out again).
Place peaches in the middle of the circles and squares. Separate the egg. For the windmills, cut corners of the squares. Fold every other corner to the middle, spread with egg white and stick. Put them on a baking tray covered with baking paper.
Whisk the egg yolks and spread them on the cakes. Bake in the preheated oven (electric oven: 200°C/ gas: level 3) for 10-15 minutes. Cut circles up to the peach five times, fold over one corner at a time and press on the cake, spread with egg white.
Place the pieces on a baking tray, brush with egg yolk and bake in a preheated oven (electric oven: 200°C/ gas: level 3) for 10-15 minutes as well. Let them cool down and serve sprinkled with icing sugar.
Makes 8 pieces.