Fat Thursday is a traditional Christian feast marking the last Thursday before Lent and is associated with the celebration of Carnival. Because Lent is a time of fasting, the days leading up to Ash Wednesday provide the last opportunity for feasting (including simply eating forbidden items) until Easter. Traditionally it is a day dedicated to eating, when people meet in their homes or cafés with their friends and relatives and eat large quantities of sweets, cakes and other meals usually not eaten during Lent. Among the most popular all-national dishes served on that day are pączki in Poland or berliner, fist-sized donuts filled with rose hip jam, and angel wings (faworki), French dough fingers served with powdered sugar.

In Poland, Fat Thursday is called Tłusty Czwartek. People purchase their favorite pastries from their local bakeries. Traditional foods include pączki (doughnuts), which are large deep-fried pieces of especially rich dough, traditionally filled with plum or rose petal jam (though others are commonly used) and topped with powdered sugar, icing, or glaze. Angel wings (faworki) are also commonly consumed on this day.

via Wikidpedia