Preheat oven to 350 degrees.

Cook the spaghetti per package directions to al dente (about 8 minutes). Drain and return to the pot it was cooked in. Stir 4 tablespoons of sliced butter into the hot spaghetti.

Stir one jar of the spaghetti sauce into the cooked noodles. Set aside.

In a large skillet brown the ground beef, Italian sausage and onions. Add the garlic and cook one more minute. Drain any extra grease. Pour the remaining jar of spaghetti sauce into the meat mixture. Set aside.

In a medium size bowl mix together the cottage cheese, cream cheese, sour cream and 1 ½ cups shredded mozzarella cheese. Set aside.

In a deep dish 9x13 (or a 10x14 lasagne pan) place the remaining 4 tablespoons butter slices into the bottom of the pan.

Spread half of the spaghetti noodles in the bottom of the pan.

Next spread the cheese mixture over the noodles.

Next place the remaining spaghetti noodles over the cheese mixture.

Pour the meat sauce on top of this layer of spaghetti.

Sprinkle the remaining 1 ½ cups of mozzarella cheese on top of the casserole.

Bake for 30-40 minutes. Let the casserole sit 5-10 minutes before serving.