Billion Dollar Spaghetti

1 (8 ounce) package spaghetti

1 pound Italian sausage

1 (16 ounce) jar spaghetti sauce

½ cup stick butter, sliced and divided

1 (8 ounce) container ricotta cheese

1 (8 ounce) package cream cheese, softened

¼ cup sour cream

1 (8 ounce) package shredded mozzarella cheese

Preheat oven to 350 degrees. Bring a large pot of lightly salted water to a boil. Cook spaghetti in boiling water, stirring occasionally until cooked through but still firm to the bite, about 12 minutes. Drain spaghetti. Heat large skillet over medium-high heat. Cook and stir sausage in skillet until browned and crumbly, about 5 to 7 minutes. Drain sausage and discard grease. In a bowl mix sausage and spaghetti sauce. Place half of the slices of butter in the bottom of a 9X13-inch casserole dish. Spread half the spaghetti into the dish. Mix the ricotta cheese, cream cheese, and sour cream together in a bowl. Spread half of the mixture onto spaghetti, then layer with half of the sausage and spaghetti sauce. Place remaining half of spaghetti on top, place remaining butter on top. Layer remaining cream mixture on top and top off with remaining sausage and sauce mix. Bake in oven for 30 minutes. Spread mozzarella cheese over casserole and continue baking until cheese has melted and is lightly browned, around 15 more minutes.