Grind the cottage cheese. Sift the flour through a sieve. Separate the yolk from the white, beat the white. To serve, wash and dry the berries on paper towels. Preheat the oven to 240-260 degrees. Line a baking tray with baking paper.
Do the test. Combine the mashed cottage cheese with the yolk, salt and butter. Stir until smooth, gradually adding flour. Leave in a cool place for 15-20 minutes.
Prepare the dough for baking vol-au-vents. Roll out the dough to a thickness of 5 mm. Using glasses, make circles - first with a glass with a larger diameter, and then cut out the middle of half the circles with a glass with a smaller diameter. Connect large circles with rings, glue them with protein.
Prepare the filling and finish cooking the dish. Mix cottage cheese, sour cream, sugar, flour, salt and vanilla sugar into a homogeneous mass. Fill the vol-au-vents with it. Brush the top with beaten egg. Place the product blanks on a baking sheet lined with paper and bake in a preheated oven for 15-20 minutes.
Decorate the curd vol-au-vents with fresh berries before serving.