Enjoy the flavors of stuffed shells without the hassle with this unstuffed shells casserole. This easy-to-make dish features jumbo pasta shells filled with a savory mixture of ground beef, spinach, and ricotta cheese, all baked in a rich tomato sauce. Topped with melted mozzarella cheese, every bite is cheesy and satisfying. Whether you're feeding a crowd or looking for a comforting weeknight dinner, this casserole is sure to please.