Peel and grate the cooked potatoes.

Place in a bowl, add the egg and the salt and knead until smooth.

Add the flour one cup at a time until the dough is less sticky.

Turn out the dough on a lightly floured surface and knead. Use more flour if the dough is too sticky.

Roll the dough out and use a glass or a 3" inch in diameter round cutter to create circles.

Add a teaspoon of plum jam to the middle of each circle, fold in half and seal the edges using a fork.

Place a layer of paper towels next to the stove.

Bring a large pot of salted water to a boil.

Boil the pirohy. They will sink to the bottom and will pop up when they are done.

Use a skimmer or slotted spoon to remove the pirohy from the boiling water and place on the paper towels to drain. Pat gently with a paper towel to remove excess liquid.

Transfer to a serving plate and cover with aluminum foil to keep warm.

In a small skillet, melt the butter. Cook over medium heat stirring until the butter turns brown.

Pour the butter over the top of the pirohy, then sprinkle with poppy seeds.

Load the powdered sugar into a small strainer, sprinkle over the top of the pirohys and serve.