Boil about 2 pounds of starchy potatoes in salted water for 20-25 minutes until fork-tender. Peel and mash until smooth.

In a bowl, combine mashed potatoes with 1 teaspoon of fine salt, 1 tablespoon of melted butter, 1 cup of all-purpose flour, and 1/4 cup of wheat semolina. Mix until a soft dough forms.

Wash 12 small plums, slice them in half, and remove pits. Sprinkle sugar inside if desired.

Divide the dough into 12 equal portions and wrap each around a plum half. Seal tightly.

In a large pot, bring salted water to a boil. Drop in dumplings and simmer for 12-15 minutes until they float.

Melt 4 tablespoons of butter in a skillet. Add breadcrumbs, 1/4 cup of ground hazelnuts, 2 tablespoons of sugar, and a pinch of cinnamon. Toast until golden brown.

Coat the cooked dumplings in the breadcrumb mixture and dust with powdered sugar before serving.