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 ...