Pour hot milk over the ground poppy seeds and set aside to cool - for me, the poppy seeds absorbed all the milk. If the poppy seeds are still wet after cooling, line a fine-mesh sieve with gauze/muslin cloth/paper towels and pour the poppy seeds through the sieve to remove excess water.

Briefly blend the eggs with powdered sugar and butter.

Add the egg mixture to the poppy seeds and mix.

You can now add some almond extract if you are using it.

Divide the poppy seeds into 3 roughly equal portions.

Add a teaspoon of sugar to the yeast and rub them together thoroughly - the yeast should become liquid.

To the flour, add the butter cut into smaller pieces, sugar, vanilla sugar, egg yolks, and yeast.

Briefly chop everything together - you can do this with a knife, or like me, in a food processor.

Knead the dough - if the dough doesn't stick together well, add a little cold water.

Divide the finished dough into 4 equal portions.

Roll out each portion of dough very thinly (for me, it was about 2 mm) to the size of the baking pan. It's a good idea to roll it out directly on baking paper, as it makes it easier to transfer the dough to the pan.

Place the first layer of dough in the baking pan along with the baking paper.

Spread one portion of the poppy seed filling evenly over the dough.

Place the second layer of dough, using the baking paper to help - I flipped it upside down and carefully peeled it off. Cut off any excess pieces on the sides with a knife and attach them where the dough is missing.

Place poppy seeds on the dough, then place the next layer of dough, and then poppy seeds again.

Arrange the last piece of dough.

Cover the baking pan with the dough with plastic wrap and leave it in a warm place overnight.

In the morning, remove the plastic wrap from the dough and bake the poppy seed cake at 190 degrees (top-bottom mode) for about 40 minutes. If the top of the cake starts to brown too much, cover it with aluminum foil during baking.

After baking, cool the cake.

Pour the powdered sugar into a bowl.

Add milk one tablespoon at a time until you get a slightly liquid icing.

Spread the icing over the cake.