This comforting baked pasta feeds a crowd and is an easy way to upgrade everyday spaghetti with meat sauce. Once baked, the spaghetti casserole slices into neat squares, and the layer of ricotta and Parmesan filling give it the rich flavor of a lasagna. Feel free to play around with the recipe, swapping in Italian sausage or ground turkey for the ground beef and sautéing leftover vegetables and adding them to the sauce. If you’re planning in advance, you can assemble the casserole (through the end of Step 5) and store in the refrigerator, covered, until ready to bake.