For Bohemian Kolatschen prepare a yeast dough from the given ingredients for the dough.
Mix the curd with butter, sugar, egg yolks, rum and starch. Whip the egg whites to egg whites and fold into the curd mixture.
Mix the poppy seeds with the sugar, milk and breadcrumbs, bring to the boil once and then allow to cool.
Divide the yeast dough into 50 g pieces, form a pancake with an edge from each piece and brush the edge with egg yolk. Cover each piece of dough with curd or poppy seed mixture and a heap of Powidl and fold into Kolatschen. Let the kolaches rise for 10 minutes. Preheat the oven to 200 degrees Celsius and bake the Bohemian Kolatsches on the second rack from the bottom for 20-25 minutes.