Preheat oven to 350 F.

Cook the pasta according to the package instructions. Drain and return the spaghetti to the pot you cooked it in and stir in one bottle of the spaghetti sauce. Set aside.

Heat the oil in a large skillet over medium heat.

Add the onion and cook for 5 minutes.

Crumble in the raw sausage and stir, cooking until the sausage is cooked through. I used a wooden spoon to help break up the sausage while it cooked.

Stir in the garlic and cook for 1 more minute.

Remove from heat and stir in the remaining jar of spaghetti sauce.

In a bowl, combine the Ricotta, cream cheese, sour cream, Italian seasoning and 1 cup of the Mozzarella.

Place 8 of the pieces of butter in the bottom of a 9" x 13" baking dish.

Place half of the spaghetti mix into the bottom of the dish. Use a spatula to spread it out evenly.

Add the cheese mixture and spread out evenly.

Add the remaining butter and then add the rest of the of the spaghetti mixture. Spread out evenly.

Add all of the tomato sauce mixture and spread out evenly.

Add the remaining mozzarella cheese.

Bake for 35-45 minutes until hot.

Let rest for 10 minutes before slicing.