Mix flour and baking powder in a bowl and press a depression in the middle. Add 2 eggs, sugar, vanillin sugar and salt to the hollow and mix with some flour from the rim to a thick paste. Cut butter into cubes and add it to the porridge with curd cheese and 1 tablespoon rum. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough
Mix the poppy seed filling and 1 egg. Lightly dust a large sheet of baking paper with flour. Roll out the dough into a rectangle (approx. 40 x 45 cm). Spread the poppy seed mixture on the dough, making the edges slightly thinner. Now roll the dough from the two long sides towards the middle. Press the two end sides (narrow sides) well together. Cut both strands slightly at regular intervals. Lift the wrapped cake on the baking paper into a flat roasting pan or a roasting lid. Bake in the preheated oven, 2nd rail from below (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 50 minutes. Mix egg yolk and cream. After approx. 30 minutes spread the cake with the egg yolk and cream
Mix icing sugar, approx. 1 tablespoon rum and lemon juice to a thick icing. Spread a thick layer of the hot wrap cake and let it cool down on a cake rack. Serve with butter as desired