Dissolve the yeast in slightly warmed milk, add 1 tablespoon sugar and flour. Stir well and leave to rest for 15-20 minutes. Sift the flour into a large tray and add the ready yeast and all remaining products (be sure to dissolve the baking soda in yoghurt first).
Knead the dough, melt the butter and gradually knead it into the dough. Allow the dough to rise for 30 minutes. Knead it again and let it rise for another 30 minutes. Spread out the dough in a greased tray and optionally, make some decorations with a fork or knife.
Smear the sweet round loaf with a yolk beaten with a little oil and put it to bake in a moderate preheated oven for about 30 minutes.