Boil a pot of water and cook rigatoni until al dente. Drain and set aside to cool.
In a medium bowl, mix together the ricotta, 3 Tbsp. Parmesan, and egg until creamy. Add in garlic, spinach, basil, onion, and salt until thoroughly mixed. Set aside.
Spray a 9x13 baking dish with olive oil spray until coated. Add half of the cooked pasta to the dish, making sure the bottom of the pan is covered. Gently pour half of Dei Fratelli Tomato Puree over the pasta and coat evenly.
Add all of the ricotta mixture on top. Be sure to spread it evenly around the dish. Top with 3/4 cup of mozzarella.
Add the rest of the rigatoni evenly. Top with remaining Dei Fratelli Tomato Puree, then with the remaining parmesan and mozzarella cheese.
Place foil over the baking dish and bake for 20 minutes. Remove foil and broil until cheese is golden brown, about 3-5 minutes.