Line baking tray with baking paper. Coarsely grate marzipan. Separate 1 egg. Marzipan,
Mix 1 egg, 1 egg white and 2-3 tbsp. milk with the whisk of the hand mixer until creamy
Melt butter at low heat. Mix quark, 8 tablespoons milk, sugar, vanillin sugar and 1 pinch of salt. Add liquid butter slowly while stirring with a hand mixer. Mix 450 g flour and baking powder, stir half of it briefly into the quark mixture. Knead the rest with the dough hooks of the hand mixer, then knead with lightly floured hands
Roll out the dough on some flour to a rectangle (approx. 25 x 55 cm). Spread with the marzipan cream, leaving 2 cm free at the edge, roll up from the long side, lay on the tray to form a wreath and press the ends together. Place an externally greased tin in the middle. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 20 minutes
Whisk 1 egg yolk and 1 tablespoon of milk. Brush the wreath with it and continue baking for about 10 minutes. Mix icing sugar and lemon juice. Take the wreath out of the oven and remove the tin. Coat the wreath immediately with the icing, sprinkle with sugar crystals. Cool down