Preheat oven to 350 degrees. Spray a 9x13 glass baking dish with cooking spray.
Cook spaghetti al dente according to package directions. Drain and place in large mixing bowl.
In another mixing bowl, stir together sour cream, ricotta, half-and-half, mozzarella, oregano, basil, pepper, garlic, salt, and 1/4 cup of the Parmesan cheese.
Add above cheese mixture to the spaghetti. Mix gently until spaghetti is evenly coated with mixture.
Gently place spaghetti mixture into prepared dish. Top with remaining 1/4 cup Parmesan cheese. Cover dish with aluminum foil and bake at 350 degrees in pre-heated oven for 30 minutes.
Remove from oven, remove foil and place dish on cooling rack for 10 minutes.
While pasta is cooking, prepare the meat sauce. For the meat sauce: Add ground beef in a skillet over medium heat and brown meat well. Add salt and pepper. Add the onion and cook until soft. Drain meat and set aside. Add spaghetti sauce and let simmer for about ten minutes.