01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish.
02 - Boil salted water in a large pot. Cook ziti until nearly al dente, about 1–2 minutes less than package directions. Drain and set aside.
03 - Heat olive oil in a large skillet over medium heat. Cook onion until soft, about 3–4 minutes. Add garlic and sauté for 1 minute until fragrant.
04 - Add marinara sauce, oregano, and basil to skillet. Season with salt and pepper. Simmer for 5 minutes, then remove from heat.
05 - In a large bowl, mix cooked ziti, 2 cups mozzarella, ricotta, half the Parmesan, and half the marinara sauce. Toss gently to combine.
06 - Spread half the pasta mixture in baking dish. Top with half remaining marinara and half remaining mozzarella. Repeat layers, then sprinkle with remaining Parmesan.
07 - Cover dish with foil and bake for 20 minutes. Remove foil and bake 10–15 minutes more until cheese is bubbly and golden.
08 - Let baked dish rest for 10 minutes. Garnish with torn fresh basil before serving if desired.