Add the egg to the “revived” yeast and whisk. Add sugar, zest from one lemon, salt, warm milk, sour cream. Mix well, add flour, first 2.5 cups, knead the dough. Add softened plums. oil. If necessary, add a little more flour, but do not rush. After kneading the dough, add vegetable oil. The dough turned out to be soft, obedient, departs from the hands, elastic. Cover it and leave it in a warm place to come up for 30-40 minutes.