This pierogi casserole has become a huge family favorite. Layers of cheese pierogi are layered with Alfredo sauce, sliced green onions, and sliced sausage!
Preheat oven to 350ºF (177ºC). Spray a 9x13“ baking dish with nonstick cooking spray. Spray one side of a large piece (sized to cover the baking dish.) of aluminum foil with nonstick cooking spray; set the dish and foil aside.
Spread half the frozen pierogies in a single layer in a prepared baking dish.
Spoon half of the alfredo sauce over the pierogies.
Spread half the kielbasa over the pierogies and sauce.
Sprinkle half the green onions over the sausage.
Sprinkle half the cheese over the onions.
Repeat one more layer of each. Cover with prepared foil and bake in the preheated oven for 20 minutes. Remove foil and continue to bake until heated through and bubbly, about 20-25 minutes.