Wash the raisins, dab dry and soak in rum. Melt the fat, add the milk, warm up lukewarm. Put flour, sugar, vanillin sugar, egg, salt and crumbled yeast in a mixing bowl. Add milk-fat mixture and knead with the dough hooks of the hand mixer to a smooth dough. Cover and leave to rise in a warm place for about 40 minutes. Knead the marzipan to a smooth dough and roll out between 2 layers of cling film (approx. 36 x 40 cm). Knead the yeast dough again well and roll out into a rectangle (approx. 36 x 40 cm) on a floured work surface.
Place a marzipan plate on top and sprinkle with the raisins. Roll up the yeast dough from the short side, cut into approx. 15 slices. Place 5 snails on a baking tray lined with baking paper and let them rise for another 15 minutes. Bake one after the other in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 15-20 minutes. Stir icing sugar, lemon juice and 1 tablespoon of hot water until smooth. Remove snails from the oven, let them cool down a little and coat them with icing