Dough
Soften the butter then cream together with the sugar until fluffy. Add the eggs and mix to combine.

Mix in the sour cream and salt.

Sift in the flour, a small amount at a time, and mix to combine.

Neutralise the baking soda with one or two drops of vinegar. When it has finished foaming, stir the baking soda in to the mix.

Knead the dough until smooth and firm. Set aside while you prepare the filling.

Filling
If you are using a store bought soft cheese, such as quark or ricotta, make sure you drain it well first so it is very dry.

Combine all the filling ingredients together and mix until well combined.

Preparing the Sochniki
Roll out the dough until it is 3-4mm thick and cut into large circles. Put 2 heaped teaspoons of filling into one half of each of the circles of dough. Bring the edges together and pinch the sides together, leaving the centre open.

Preheat the oven to 180 degrees C.

Grease a baking tray with butter or cooking oil and lay the sochniki down on their sides. Glaze the tops with beaten egg.

Bake for 25 minutes until very lightly golden.