Knead the yeast and melt it in 50 ml of warm milk.
Boil 50 g of sugar with 150 ml of milk over low heat. Add the poppy seeds and 50 g of butter.
Bring to the boil for 5 minutes, stirring constantly, add the rum essence and leave to cool.
Put the flour in a bowl, make a hole in the middle, add the yeast mayonnaise, 250 ml of milk and salt. Knead until it becomes a thick dough, gradually add the remaining melted butter and margarine.
When the dough no longer sticks, cover with a towel and leave to rise for half an hour.
Line a cake pan with baking paper. Divide the dough into equal parts (depending on the tray and how high you want it to be).
Spread the rectangular sheets, spread a layer of poppy seeds evenly.
Roll the sheets, put them in the pan. Grease with beaten egg.
Bake for 30-45 minutes.