For the dough, work the butter, flour, sugar, baking powder, 1 egg and a pinch of salt into a dough. Line a greased springform pan with it.
For the poppy seed mixture, bring 1 liter of milk with 1 cup of sugar, 1 cup of poppy seeds and 125 g of butter to the boil, then slowly stir in 1 cup of semolina. Bring to the boil again briefly and when the mixture has cooled down, add 4 eggs, raisins, almonds and rum flavoring (depending on your taste).
Pour the poppy seed mixture into the mold on the bottom. Brush with a whisked egg yolk.
Bake in a preheated oven at 180 ° C for about 50 minutes.