Creating the perfect Meatless Baked Ziti with Ricotta can be straightforward by following these easy steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Cook Ziti: Bring a large pot of salted water to a boil. Cook the ziti according to package instructions until al dente. Drain and set aside.
3. Prepare Sauce: In a large skillet, heat the olive oil over medium heat. Add diced onion and sauté until translucent, about 5 minutes. Stir in minced garlic and cook for another minute.
4. Combine Tomatoes & Spices: Add the crushed tomatoes, oregano, basil, red pepper flakes, and season with salt and pepper. Simmer the sauce for about 10 minutes to let the flavors meld.
5. Mix Cheeses: In a separate bowl, combine ricotta cheese, half of the mozzarella cheese, and half of the Parmesan cheese. Stir until smooth and consistent.
6. Assemble Ziti: In a large mixing bowl, combine the cooked ziti with the tomato sauce. Toss well to coat the pasta evenly.
7. Layer the Casserole: In a 9×13 inch baking dish, spread half of the ziti mixture. Top with spoonfuls of the ricotta mixture, then spread the remaining ziti over the top.
8. Top with Cheese: Sprinkle the remaining mozzarella and Parmesan cheese over the final layer of ziti.
9. Bake: Cover the baking dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the top is golden and bubbly.
10. Cool and Serve: Once baked, remove from the oven and let the ziti cool for about 10-15 minutes before serving. This allows it to set a bit, making it easier to slice.