Cook the potatoes: Boil peeled potatoes in salted water until tender. Drain well and mash until smooth. Let cool slightly.
Make the dough: Mix mashed potatoes with flour, egg, butter, and salt until a soft dough forms.
Prepare the plums: Pit each plum and place a sugar cube (or a pinch of cinnamon sugar) inside.
Form the dumplings: Roll dough on a floured surface to about ¼ inch thickness. Cut into squares, place a plum in the center, and wrap dough around it to form a ball.
Cook the dumplings: Bring a large pot of salted water to a boil. Add dumplings and cook 8–10 minutes, until they float to the surface.
Prepare the coating: In a skillet, melt butter and toast breadcrumbs until golden. Stir in sugar and cinnamon.
Finish: Roll the cooked dumplings in the toasted breadcrumbs until coated.
✨ Serve warm with extra sugar or cinnamon sprinkled on top.
