Bring a large pot of lightly salted water to a boil. Cook pasta in boiling water until al dente. Drain.
Meanwhile, cook ground meat and onion in a frypan over medium heat, stirring frequently until meat is browned. Stir in pasta sauce, reduce heat and simmer for 15 minutes.
Preheat oven to 180 degrees C. Lightly grease a 20x30cm baking dish. Layer the ingredients in the prepared baking dish as follows: half of the cooked pasta, all the provolone cheese, all the sour cream, half of the sauce mixture, remaining pasta, mozzarella cheese and remaining sauce mixture. Top with grated Parmesan cheese.
Bake in preheated oven for 30 minutes or until bubbly.