Preheat oven to 375°F (190°C).
- Cook pasta in salted water until just al dente. Drain and set aside.
- In a skillet, heat olive oil over medium heat. Sauté diced onion until soft, about 3–4 minutes. Add garlic and cook for 1 minute.
- Add ground beef or sausage and cook until browned. Drain any excess fat.
- Stir in pizza sauce, Italian seasoning, salt, and pepper. Simmer for 5 minutes.
- In a large bowl, mix the cooked pasta, meat sauce, and half of the mozzarella cheese.
- Transfer mixture to a greased 9×13-inch baking dish. Top with remaining mozzarella and cheddar cheese, then layer pepperoni and optional toppings.
- Bake uncovered for 20–25 minutes, or until the cheese is melted and bubbly.
- Let rest for 5 minutes before serving.