Cut washed rhubarb and white or brown bread into cubes. Add both to the water, season with 2 cloves and cinnamon bark and cook. Stir in sugar and let it boil repeatedly. Mix one egg yolk in sour milk or whipped cream and add to the soup, which has been removed from the fire, stirring quickly. Whip the egg whites with 1 sachet of vanilla sugar until stiff and place on top of the soup, cut into small dumplings. You can add cherries, pear pieces, strawberries or currants to the cooled soup.