Step 1

Stir sugar and yeast into warm milk; set aside until it bubbles, 15 minutes.

Step 2

Melt butter in microwave oven; set aside to cool to room temperature. Beat together powdered sugar, whole eggs and yolks in small bowl until well-combined.

Step 3

Beat in rum. Set aside.

Step 4

Place flour, salt, yeast mixture and egg mixture in bowl of electric mixer with paddle attachment. Beat until flour is combined and dough is stretchy, about 3 minutes. (Or beat by hand 10 minutes.) Add melted butter; mix until well-combined, about 1 minute. Cover bowl with towel; let stand in warm place until doubled in size, about 1 1/2 hours.

Step 5

Place dough on lightly floured surface. Stretch and pat until 1/4 inch thick.

Step 6

Cut into 3 inch circles using glass or biscuit cutter. Place1/2 teaspoon of the filling in center of each circle. Fold dough over filling; pinch edges together, making a ball. Place on floured parchment or wax paper. Cover with towel. Let stand in warm place 45 minutes.

Step 7

Heat shortening in deep-fat fryer, deep saucepan or wok until deep- frying thermometer reaches 360 to 370 degrees F. Have hot fat at least 3 inches deep.

Step 8

Fry paczkis, a few at a time, until brown on all sides, about 4 minutes. Drain on paper towel-lined plate. Sprinkle with powdered sugar while still warm.