Vatrushka ( Russian: ватрушка) is an Eastern European pastry (pirog) formed as a ring of dough with quark in the middle, sometimes with the addition of raisins or bits of fruit. The most common size is about 5–10 cm (2–4 in) in diameter, but larger versions also exist. Vatrushkas are typically baked using a sweet yeast bread dough. Savoury varieties are made using unsweetened dough, with onion added to the filling.