Take all the ingredients for the dough out of the refrigerator. Mix the flour (I didn't even sift it) with the sugar, a pinch of salt, and the baking powder. Add the cold butter, cut into cubes, to the flour and quickly chop it until it becomes crumbs. Don't try to make the crumbs perfectly uniform; they don't have to be.

Make a well in the sifted flour, add the egg yolks and sour cream, quickly knead the dough, and place it in the refrigerator covered with a towel.

Remove the dough and roll it out into a rectangular shape. Add the vanilla sugar to the egg whites and begin beating them at low speed. Then increase the mixer speed and gradually add all the sugar. Beat until stiff peaks form. Spread the cream mixture over the dough, leaving a little space around the edges.

Sprinkle with walnuts and cranberries and roll the dough into a log, sealing the edges as tightly as possible.

Transfer the roll onto a board with the seam facing down (if you have been working with a silicone mat) and, using a sharp knife, cut the roll into pieces approximately two centimeters long. Preheat the oven to 200°C (392°F). Transfer each piece to a baking sheet lined with parchment paper, leaving a small space between them, then press them down and round them slightly.

Bake for 25 minutes in a top-down oven.

Enjoy!