Mix all the ingredients for the dough together and let rest for an hour.
Then form the dough into a roll and cut 10 equal slices.
Cover each slice with a washed plum and form the whole into a smooth dumpling with wet hands.
Cook the dumplings for about 15 minutes in boiling salted water, stirring the water with the handle of a wooden spoon, so that the plum dumplings do not stick to the bottom of the pot. When the dumplings float to the surface, they are done.
For the buttered dumplings, simply melt the butter and mix with the breadcrumbs, nuts and sugar and fry until slightly crispy.
Roll the plum dumplings fresh from the water in the breadcrumbs and serve sprinkled with powdered sugar.