Lightly grease a 9x13-inch baking dish and set it aside.
Place a large non-stick skillet over medium heat, add the oil. Once the oil is hot, add the onion and cook until soft.
After that, add spinach, cook and stir until wilted. If you don't like spinach, leave it out.
Next, add garlic, basil, salt and pepper. Stir and cool for 1 minute.
Meanwhile, bring a large pot of water to a boil. Add 1 teaspoon of salt and ziti and cook for 8 to 10 minutes or until al dente. Drain and rinse with cold water.
In a bowl combine the cooked ziti, ricotta cheese, mozzarella cheese, pepper jack cheese, egg, spinach mixture and 1 1/2 cups spaghetti sauce, stir to combine.
Transfer the mixture into the prepared baking dish. Top with remaining spaghetti sauce, then sprinkle with Parmesan cheese on top.