Linzer Tart with Apricots

Mix the softened butter with sifted flour, powdered sugar, and 1 egg yolk, and knead into a smooth dough. Wrap it in cling film and let it rest in the refrigerator for 12 hours. Then, on a floured surface, roll out the dough into a 5 mm thick sheet and line the baking pan with it.

Preheat the oven to 180 °C.

Mix the remaining egg yolks, vanilla sugar, and sour cream together.