Preheat the oven to 350°F (175°C). Butter a 9x13-inch baking dish.

Bring a large pot of lightly salted water to a boil. Cook ziti pasta until al dente, about 8 minutes. Drain.

In a large skillet, brown the ground beef and chopped onion over medium heat. Stir in the spaghetti sauce and let it simmer for 15 minutes.

Spread half of the cooked ziti in the bottom of the prepared baking dish. Layer with provolone cheese slices and sour cream.

Add half of the meat sauce over the sour cream layer.

Top with the remaining ziti, shredded mozzarella cheese, and the rest of the meat sauce.

Sprinkle grated Parmesan cheese on top.

Bake in the preheated oven for about 30 minutes, until the dish is heated through and the cheeses are melted and bubbly.