Cook spaghetti, drain and set aside. Saute ground beef with onion, garlic and green pepper cook beef till brown, drain and add spaghetti sauce, set aside. Combine cottage cheese, cream cheese, sour cream, pepper and garlic salt in a bowl. In a 9x13 inch greased pan, spread 1/2 of the spaghetti noodles in the pan and drizzle 3 tablespoon of melted butter on top , cover with cheese mixture, and add remaining spaghetti. drizzle the rest of the melted butter over spaghetti, and then spread the meat mixture on and top with shredded cheese. Chill for a hour (can be refrigerated overnight), and remove from fridge 20 min. before baking. Bake at 350°F for 45 minutes.