Stir yeast and 1 tablespoon of sugar until the yeast is liquid. Warm the milk lukewarm. Knead 500 g flour, 1 pinch of salt, 50 g sugar, 50 g soft butter, milk and yeast to a smooth dough. Form dough into a ball and let it rise covered in a warm place for about 1 hour.
For the crumbles, coarsely grate marzipan. Melt 150 g butter. Knead 300 g flour, 150 g sugar, 1 pinch of salt, marzipan and liquid butter into crumbles. Wash the redcurrants, drain well, remove the berries from the panicles.
Cream double, vanilla sauce powder and 30 g sugar mix.
Roll out yeast dough on a floured work surface to form a rectangle (approx. 50 x 35 cm). Spread cream on top. Sprinkle with currants and approx. 1/4 sprinkles. Roll up the dough from the short side.
Cut into approx. 16 slices and spread on 2 baking trays lined with baking paper. Sprinkle with the remaining crumbles.
Cover and leave to rise in a warm place for about 45 minutes. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) one after the other for approx. 25 minutes. Mix icing sugar and 4 tablespoons of water with the whisk of the hand mixer until smooth.
Take the snails out of the oven and spread the icing on them.