In a Dutch oven, cook beef over medium heat until no longer pink; drain. Add the tomato sauce, salt, pepper and garlic powder. Bring to a boil. Reduce heat; simmer, uncovered, for 15 minutes.
In a mixing bowl, beat cream cheese until smooth. Add sour cream, 1 cup cheddar cheese and green onions; mix well.
Spread about 1/2 cup meat sauce into two greased 8-inch square baking dishes. Place two to three noodles in each dish, trimming to fit if necessary. Top each with about 1/2 cup cream cheese mixture and about 2/3 cup meat sauce. Repeat layers twice. Sprinkle 1/2 cup cheddar cheese over each.
Bake casseroles, uncovered, at 350 degrees for 25-30 minutes or until bubbly and heated through. Let stand 15 minutes before cutting.