Wash the potatoes thoroughly, grate them dry, wrap them in aluminium foil and cook them in a preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: level 2) for 1-1 1/2 hours until soft. For the compote, wash the plums, halve, stone and cut into slices.
Caramelise sugar and vanilla sugar in a pan, deglaze with red wine and redcurrant juice and let it boil down for about 5 minutes at medium heat. Mix 2 teaspoons of starch with a little cold water and thicken the stock with it, bring to the boil again.
Add the plums and let the stock cool down. Peel the potatoes and press them twice through the potato press while still hot. Stir 1 egg yolk into the mixture with a wooden spoon. Gradually fold in 30 g of potato starch until it is completely absorbed.
Knead 25 g soft butter into the dough and season with 1 pinch of salt. Season the plum puree with rum and the zest of 1 orange. Roll out the potato dough thinly on a floured work surface and cut out circles (8 cm Ø).
Place the damson jam on one half of a circle. Whisk 1 egg yolk and brush the edges of the circle with egg yolk. Fold the other half over and press down lightly with a fork. Bring plenty of water to the boil in a large saucepan and salt lightly.
Add the Powidltascherl, reduce the heat and let it stand for 5-8 minutes. Melt 50 g butter in a pan. Stir in the zest of 1 orange and lemon, season with cinnamon and finally add breadcrumbs.
Stir until the crumbs have completely absorbed the fat and are dry again. Remove the Powidltascherl from the water with a skimmer, drain well and roll in the crumbs. Arrange the stewed plums with the pouches on plates and dust with icing sugar.