MAKE AHEAD: First, boil the potatoes in their skins in advance. Let them cool down completely.
Peel the cooked, cooled potatoes and grate them finely. Add the flour, eggs, cream cheese, and a pinch of salt to the bowl.
Work into a smooth, non-sticky dough. Add a little flour if necessary.
Shape the dough into a cylinder and cut it into equal-sized pieces on a floured surface.
Lightly press each piece of dough into the flour on both cut sides and shape it into a flat patty.
Wrap the halved plum in the dough and shape it into a round dumpling.
Cook the plum dumplings in gently boiling water for 8-10 minutes. There is no need to flip the dumplings during cooking.