• Boil the potatoes with their skin on, until soft. Peel them and mash them well, you can also use a grater. Let cool completely.

Prepare the toasted breadcrumb mixture.

• Meanwhile, in a medium frying pan mix well breadcrumbs with oil and cook on low-medium heat until golden brown.
• Stir constantly to prevent burning. Remove from heat and set aside to cool.
• When cool enough stir in sugar, a pinch of salt and cinnamon. 

How to make the potato dough and shape the dumplings.

• In a large bowl mix the mashed potatoes with egg, butter and flour until they bind together. knead until a smooth, sticky dough is formed. 
• Bring a large pot of water to boil then reduce the heat to a low simmer.
• Take a walnut size of the potato dough and form small balls after inserting one dry plum in the middle of each.
• Put the dumplings into the hot water. Let the dumplings boil until they come to the surface of the water. Let them boil on the surface another 2 more minutes and they are done. Remove the dumplings with a perforated spoon and roll them in the breadcrumb mixture. 
• Sprinkle the rest of breadcrumbs mixture or sugar over the dumplings and serve hot or cold.