Preheat your oven to 350 degrees F. Spray a 9x13 deep baking dish with cooking spray.
While the pasta is cooking, cook ground beef and onion in a large sauté pan or Dutch oven over medium heat, crumbling the beef with a wooden spoon as it cooks. Cook until beef is browned and no longer pink. Drain off fat.
Add garlic, Italian seasoning, salt, and pepper. Stir and cook until garlic is fragrant (about 30 seconds).
Add marinara sauce and stir to combine. Simmer for 5 minutes, stirring occasionally.
Evenly spread ½ of the cooked and drained ziti in the bottom of the baking dish. Arrange slices of provolone cheese over the ziti. Dollop the ricotta cheese evenly over the provolone cheese. Spoon ½ of the meat sauce over the ricotta cheese.
Layer the remaining ziti, HALF of the mozzarella cheese, and the remaining sauce mixture.
Evenly sprinkle with the reamining mozzarella cheese and Parmesan cheese.
Bake (uncovered) for 30 to 35 minutes or until the cheese is melted and bubbling around the edges. Turn your oven broiler on high and broil for approximately 2 minutes or until the top is browned (watch carefully while broiling, as oven broilers vary).
Allow to cool 10 minutes before serving. Sprinkle with chopped fresh parsley when serving if desired.