Dissolve the yeast in lukewarm milk and mix a pre-dough with a part of 500 g flour and 2 tablespoons of sugar. Cover and leave to rise for about 15 minutes. In the meantime chop cherries finely and soak in rum.
Knead 50 g sugar, vanilla sugar, 1 pinch of salt and 200 g butter with the flour and predough to a smooth dough. Knead in the cherries. Cover and leave to rise again for about 1 hour. In the meantime, coarsely grate the marzipan and knead with the poppy seed filling.
Knead the dough again. On a floured work surface roll out rectangularly to a thickness of approx. 3 cm. Spread the dough with the poppy seed mixture, leaving a small rim. Fold in short sides approx. 1 1⁄2 cm.
Roll up the dough sheet so that the folded sides are on the outside. Press the roll a little flatter and form it into a stollen. Put it on a baking tray lined with baking paper and let it rise again covered for about 30 minutes.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Bake the stollen in a hot oven for approx. 20 minutes. Switch down (electric oven: 175 °C/circulating air: 150 °C/gas: see manufacturer) and continue baking for 30-40 minutes.
If necessary, cover with aluminium foil during the last 15 minutes of baking time.
Melt 100 g butter. Finish the stollen with butter and icing sugar. Let cool off. Packed and stored in a cool place, this Stollen will keep for at least 2 weeks.