Preheat your oven to 180°C (350°F).

Bring a large pot of salted water to a boil. Cook the pasta for 2 minutes less than package directions; it should be just under al dente. Drain and set aside.

While the pasta cooks, heat olive oil in a large skillet over medium heat. Add the chopped onion and cook for 2-3 minutes until softened. Add garlic and sauté 30 seconds.

Add ground beef or turkey to the skillet. Break it apart and cook until browned, about 5-6 minutes. Drain excess fat, if any.

Stir in tomato sauce, diced tomatoes, Italian seasoning, salt, and pepper. Simmer for 5 minutes to slightly thicken.

In a large mixing bowl, combine the cooked pasta with the meat sauce. Mix well to coat all pasta.

Spread half of the pasta mixture into a greased 9x13-inch baking dish. Sprinkle with half the mozzarella and half the Parmesan. Add the rest of the pasta, followed by the remaining mozzarella and Parmesan.

Cover loosely with foil and bake for 20 minutes. Remove the foil and bake for an additional 10-15 minutes, or until cheese is melted and bubbly.

Let the casserole rest for 5 minutes before serving. Garnish with chopped fresh basil or parsley if desired.