Drain the cranberries well in a sieve, collecting the juice. Coarsely grate the marzipan. Cream fat, sugar, marzipan, salt and vanilla sugar for about 10 minutes. Stir in the eggs one by one.
Add the crème fraiche and stir. Mix flour and baking powder and stir in briefly. Mix thickened cranberries with half of the drained cranberries. Grease a ring cake tin (2 litres capacity) and dust with breadcrumbs.
Fill half of the dough into the mould. Mix the remaining dough with the cranberries and spread it on the light-coloured dough. Marble the dough with a fork. Bake the cake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 1 1/4 hours.
Take out, let it cool for 5 minutes and turn it over onto a kitchen grid. Let it cool down. Stir icing sugar and 4-5 tablespoons cranberry juice until smooth. Spread the icing on the cake and decorate with the remaining cranberries.