1. Bring a large pot of salted water to a boil. Add the ziti and cook until just shy of al dente (about 1-2 minutes less than package instructions). Drain and set aside.

2. In a large skillet, heat olive oil over medium heat. Add the chopped onion and cook until softened, about 3-4 minutes. Add the garlic and sauté for another 30 seconds until fragrant. Then add ground beef or sausage, breaking it up with a spoon. Cook until browned and fully cooked through. Drain excess fat.

3. Stir in the crushed tomatoes, tomato sauce, tomato paste, oregano, basil, red pepper flakes (if using), salt, and pepper. Simmer the sauce on low for 15-20 minutes to blend the flavors. Taste and adjust seasoning as needed.

4. In a small mixing bowl, combine the ricotta cheese with the egg and half of the grated Parmesan. Stir until smooth.

5. In a large bowl, mix the cooked ziti with about 2 cups of the meat sauce and half of the ricotta mixture. Stir in half of the shredded mozzarella and gently fold to coat the pasta evenly.

6. Preheat oven to 375°F (190°C). Spread a thin layer of meat sauce in the bottom of a 9×13-inch baking dish. Add half the pasta mixture, followed by dollops of the remaining ricotta. Spoon more meat sauce over the top, then add the rest of the pasta. Finish with remaining meat sauce, mozzarella, and Parmesan.

7. Cover the dish with aluminum foil and bake for 20 minutes. Remove foil and bake another 10-15 minutes until cheese is bubbly and golden. Optional: broil for 1-2 minutes to brown the top.

8. Let sit for 5-10 minutes before serving. Garnish with fresh parsley or basil.