Cook egg noodles according to package directions; drain. Stir together egg noodles and chopped green onions; set aside.
Cook ground beef in a large skillet over medium heat, stirring until it crumbles and is no longer pink; drain and return to skillet. Stir in pasta sauce, diced tomatoes, and Italian seasoning.
Cut cheese loaf into 1/2-inch cubes; reserve and set aside 1 cup. Stir together remaining cheese cubes, sour cream, and cream cheese.
Spoon one-third of ground beef mixture into a 13- x 9-inch baking dish; top with half of noodle mixture and half of sour cream mixture. Repeat layers once.
Spoon remaining one-third of ground beef mixture over sour cream mixture, and sprinkle evenly with reserved 1 cup of cheese cubes.
Bake at 350° for 30 minutes or until cheese is melted and bubbly.