This vegetarian baked spaghetti casserole is a delicious and hearty dish that is perfect for a family dinner. It is made with layers of spaghetti, marinara sauce, vegetables, and cheese, all baked to perfection. The spaghetti is cooked until al dente and then layered with a flavorful marinara sauce, sautéed vegetables like bell peppers and onions, and a generous amount of cheese. The casserole is then baked until the cheese is melted and bubbly. Serve this comforting dish with a side salad for a complete meal.