Mix flour and softened butter in a food processor or chop well with a knife. Dissolve soda in matsoni/yogurt and add it, knead the dough. Then transfer the dough to a bowl, cover with a tea towel and rest for 1 hour.
In the meantime, let's prepare the filling. Mix flour, sugar, vanilla, and melted butter well and put it on the stove for 4-5 minutes, stirring continuously.
Divide the dough into several parts, roll it out, sprinkle the filling, roll it up and cut it into desired sizes with a shape knife, brush them on top and sides with beaten egg and matsoni. Bake in an oven heated to 190°C, it will take 30 minutes.Bon Appetit!