I'm not Polish but I love this annual treat (found not just in Chicago but other areas with Polish communities). And I've heard that Delightful Pastries in the city has some of the best (I saw them on Windy City Live today and they said that they made 4,000 last Thursday--or Fat Thursday, the equivalent day in Poland--and would be making 18,000 paczki today). Here you can see them in action.
Although traditional flavors are prune, plum, lemon or other berry flavors, Delightful Pastries offers the following flavors:
Apricot Jelly Paczki
Boozy Custard Paczki
Custard Paczki topped with Chocolate Fudge
Fresh Strawberry Paczki
Fresh Strawberry and Whipped Cream Paczki
Fresh Strawberry and Custard Paczki
Plum Butter Paczki
Raspberry Jelly Paczki
Rose Petal Jelly Paczki
NEW Paczki gourmet flavors:
Raspberry Chocolate Jam, made from scratch with Michigan raspberries and Belgian chocolate
Passion fruit jam, made from scratch with a great tart flavor
It actually becomes a bit of a mania in some communities. With only one day a year (or two) when these treats are available, business is brisk.
The paczki is supposed to date back to the Middle Ages, and marks the last days of excess before the Lenten season (and what a yummy excess)!