Bring a large pot of salted water to a boil. Add the 12 oz of ziti pasta and cook according to package instructions until al dente. Drain and set aside, reserving a small cup of pasta water.
In a large skillet, heat 1 tablespoon olive oil over medium heat. Add diced onion and sauté for 3-4 minutes until translucent. Toss in minced garlic and cook for another minute until fragrant.
Add 1 lb ground beef, breaking it apart with your spoon, and cook until browned and cooked through. Drain excess fat if needed.
Pour in the jar of marinara sauce. Stir in dried oregano and dried basil, and season with salt and pepper to taste. Let the sauce simmer for 5-7 minutes to meld the flavors together.
In a large mixing bowl, combine the cooked ziti, ricotta cheese, half of the shredded mozzarella, and half of the provolone cheese. Add a few spoonfuls of the meat sauce to help bind everything together. Mix gently but thoroughly. If the mixture feels too thick, add a splash of reserved pasta water.
Preheat your oven to 375°F (190°C). Spread half of the meat sauce on the bottom of the baking dish. Layer the cheesy ziti mixture over the sauce, then pour the remaining meat sauce evenly on top. Sprinkle the remaining mozzarella, provolone, and the grated Parmesan over everything.
Cover the dish loosely with aluminum foil and bake for 25 minutes. Remove the foil and continue baking for an additional 10-15 minutes until the cheese is bubbly and golden brown. Let the casserole rest for 5 minutes before serving.
Sprinkle fresh parsley over the top for a fresh pop of color and flavor. Serve warm and enjoy the comforting richness of your Baked Three-Cheese Ziti Supreme.