Preheat the oven to 325°F. Grease a 13 × 9-inch baking dish. Stir together in a large bowl:
Cook in a large pot of boiling salted water until slightly undercooked:
Drain, add to the cheese mixture, and stir together well. Pour into the prepared baking dish. Bake for 1 ½ hours. Meanwhile, stir together in a small bowl:
Sprinkle over the top of the casserole. Bake for 30 minutes more, until browned. Let stand 10 minutes before serving.