On a lightly floured surface, knead the dough vigorously (incorporate 1 to 2 tablespoons of flour if the dough sticks too much) and roll it with a rolling pin to a thickness of ⅛ inch (6mm) (or thinner for crispier chruściki).
Using a pastry wheel or knife, cut rectangles of about 2x1 inch (5 x 2,5 cm) and make an incision in the center of each rectangle. Take each rectangle and spread the incision to move one of its two smaller sides in this incision.
Deep fry in a oil preheated at 350 F / 170 c, turning chruściki halfway through cooking until very golden brown about 1 minute per side. Fry a few pieces at a time without overcrowding.
Drain and place on a plate covered with paper towels. Roll in powdered sugar or sugar.