Add the rest of the flour and knead a soft, homogeneous non-sticky dough.
Cover the dish with cling film and leave in a warm place.
When the dough has doubled in size, carefully roll it out and divide it into two parts. Roll out one part into a rectangular layer 0.5 cm thick on a table dusted with flour. Evenly grease with pre-cooked “Poppy filling”. Wrap in a roll, pinch the edges. Spread on a baking sheet seam down.
Leave for 15-20 minutes. so that the dough rises a little more. Grease the rolls with beaten egg yolk. Bake on medium level at 180 ° C for 30-35 minutes.