Cook spaghetti as directed, drain and mix with 2 Tbs. butter and 1/2 jar of sauce.
Brown ground beef with garlic and onions.
Add remaining sauce to meat mixture.
In a bowl, mix the ricotta cheese, cream cheese, sour cream and half the shredded cheese.
Place remaining pats of butter at bottom of casserole dish.
Layer: 1/2 of noodles + cheese mixture + remaining noodles + meat mixture.
Top with remaining shredded cheese and bake at 350 until heated through and cheese is melted, approximately 30 minutes.