1Crumble yeast in 1/2 cup water and 1 tablespoon sugar. Set aside for 5 minutes. Pour boiling milk over remaining 1/2 cup water, sugar and butter. Cool to lukewarm. Sift flour into bowl; add salt, eggs, milk mixture and yeast. Knead dough until smooth and elastic. Cover and let rise until doubled in bulk, about 2 hours, in a warm place.
2Crumble yeast in warm milk to which 1 tablespoon of sugar has been added and let stand 5 minutes. Mix cottage cheese with spoon until smooth. Add raisins and yeast mixture. Add unbeaten egg yolks, remaining sugar, salt, lemon zest, baking powder and flour; knead well. Set aside to rise until doubled in bulk (about 2 hours).
3When the basic dough has doubled in size, turn out onto a lightly-floured board and divide into 4 parts (one part of the basic dough is for decorating, the remaining 3 parts are for the 3 loaves). Shape three of the parts into rounds. Let basic dough stand on the board covered for 15 minutes. Take one part of the basic dough and lightly punch around the edge so that the center is elevated. Take the cheese dough divide it in thirds. Place one third of the cheese dough around the elevated edge of the basic dough; then lightly make an opening in the center. Join edges; press carefuly so that the cheese dough is completely covered. Place dough in a pan and let rise about 30-45 minutes. (Round pans or stainless steel bowls are typically used here.) Use the remaining part of basic dough to make braids, crosses, etc and attach with a little egg yolk. Brush the top with egg yolk before placing in oven. Bake for 10 minutes at 325 degrees F. Increase to 350 degrees F and bake for an additional 40 minutes.