In a bowl, combine the flour and softened butter.

Add the sour cream.

Add the vanilla sugar and a pinch of salt.

Add half a teaspoon of lemon zest, grated on a fine grater.

Knead the dough with your hands, adding a little flour if necessary, approximately 10-20 grams.

Wrap the dough in plastic wrap and refrigerate for 2 hours.

In the meantime, prepare your favorite jam; I used strawberry jam.

Chop the nuts in a blender and add them to the jam. Mix well.

After the dough has rested in the refrigerator for the specified time, sprinkle flour on the work surface, remove the dough from the foil, and roll it out with a rolling pin.

Using a round cutter or a small cup, cut out circles from the dough.

Place a teaspoon of the prepared filling in the center of the dough circle.

Close the edges of the circle with the filling to form a crescent. Repeat with the remaining circles of dough, then roll out the remaining dough again and cut out circles. I ended up with 14 crescents.

Transfer the crescents to a baking sheet lined with parchment paper. Beat an egg white with a fork, and grease each crescent with a pastry brush.

Chop the walnuts finely with a knife and arrange small pieces of walnut on each crescent. Bake in the oven at 170°C (338°F) for 15 minutes.

The nut and jam crescents are ready. Arrange them on a plate and enjoy these delicious, fluffy crescents.