Do not thaw frozen blueberries before mixing with sugar and cornstarch to prevent excess moisture. Avoid overfilling to ensure proper sealing. Seal edges firmly and remove air pockets to prevent leaking. You can pan-fry boiled pierogi in butter for a lightly crisp exterior. Dough can be made one day ahead and refrigerated; bring to room temperature before rolling.
Keyword blueberry dumplings, pierogi z jagodami, Polish blueberry pierogi, sweet pierogi