Singular Noun is Paczek (pohn-check)
Plural Noun is Paczki (punch-key)
Paczki (punch-key) Day is the feast of plenty before the Lenten fast begins. It is the last day of gaiety in Karnawal time, the period between Christmas and Lent. This is the time for sleigh parties called Kulig. To mark the last moments of excess before the austerity of Lenten sacrifice, Polish Roman Catholics celebrate Paczki Day.
On this day the traditional deep fried pastries (something like jelly doughnuts) are enjoyed throughout the world's Polonias. This joyous activity precedes the Gorzkie Zale (lamentation services) of Lent in Polonian churches. In Poland, Paczki Day takes place the Thursday before Ash Wednesday, called Tlusty Czwartek (Fat Thursday). Long lines form in front of the bakeries in Polonia, and millions of Paczki are sold.In United States Polonia, Paczki Day takes place the Tuesday before Ash Wednesday, traditionally called Fat Tuesday in Carnival. Polish American bakeries also supply Paczki in the hundreds of thousands that day. Often in American Polonia, Paczki Day is celebrated with polka dances. In Roman Catholic grammar schools throughout American Polonia, children enjoy Paczki at school on that day."