Chocolate doughnuts

Dissolve the yeast in warm water, mix with flour, add yolks, sugar and salt. Stir with a wooden spoon until air bubbles appear in the dough. Beat the whites into thick foam, put in the dough and put in a warm place for half an hour. When the dough comes up, roll it out 1 cm thick, cut out mugs with a cup and put it in a warm place again for half an hour. Fry donuts in a large amount of hot fat. Grate the chocolate, mix with icing sugar and sprinkle over the finished doughnuts.