Pączki, or oponki, (singular pączek) are a Polish filled donut. They are made with deep-fried dough shaped into spheres and filled with jam or other sweet filling, and then covered with powdered sugar, icing, glaze or dried orange zest. A small amount of grain alcohol (traditionally rectified spirit) is added to the dough before cooking; as it evaporates, it prevents the absorption of oil deep into the dough. Pączki are commonly thought of as fluffy but somewhat collapsed, with a bright stripe around them; these features are seen as evidence that the dough was fried in fresh oil.
Although they look like German berliners (North American bismarcks) or jelly doughnuts, pączki are made from especially rich dough containing eggs, fats, sugar, yeast and sometimes milk. They feature a variety of fruit and creme fillings and can be glazed, or covered with granulated or powdered sugar. Powidl (stewed plum jam) and wild rose petal jam are traditional fillings, but many others are used as well, including strawberry, Bavarian cream, blueberry, custard, raspberry, and apple.