Sour Cream Cookies with Walnut Filling

Lightly toast the walnuts in a skillet. Take the butter, egg, and sour cream out ahead of time to bring to room temperature.

In a bowl, whisk the egg with salt and sugar, then mix in the sour cream and butter.

Add the flour and baking soda, and knead into a dough.

Shape the dough into 20 equal balls and chill in the refrigerator for 30 minutes.

For the filling, finely chop the walnuts and combine them with the sugar.

Roll each ball out into a circle (8–9 cm) and make a few slits on one half of each circle.

Brush half of the circle with egg white and spoon in the filling.

Fold over, pinch the edges to seal, and roll it up into a little log.

Place on a baking sheet and brush the tops with egg yolk.