In a bowl, mix the dry ingredients: flour (300 gr.), salt (1/2 teaspoon), sugar (100 gr.). Mix all the ingredients well.
In a separate bowl, add sour cream (150 gr.), soda (1/2 teaspoon).
Add lemon juice (1 tablespoon), add lemon zest (2 tablespoons). The mixture is mixed.
In a bowl with dry ingredients, add 100 grams of cold butter. Mix flour and butter (rub) with your hands into crumbs. Then add the sour cream mixture. Knead the dough. Wrap the dough in plastic wrap and put it in the refrigerator for 30-40 minutes.
Next, roll out the cold dough into a layer 5-6 mm thick. cut out shaped products with a cutout for making cookies.
Lubricate the cookies with beaten egg and send them to the oven preheated to 180-190C. Bake the cookies until golden brown.