Cook ground beef and next 3 ingredients in a large skillet coated with cooking spray until beef crumbles and is no longer pink. Drain well, and pat dry with paper towels.
Stir together beef mixture and pasta sauce. Spoon into a 13- x 9-inch baking dish coated with cooking spray.
Prepare potatoes according to package directions, using fat-free milk. Stir together mashed potatoes and cheese sauce. Spread over beef mixture.
Bake at 350° for 30 minutes. Sprinkle with cheese, and bake 5 more minutes or until cheese melts.
Note: For testing purposes only, we used Rag Sundried Tomato & Sweet Basil sauce and Ragu Cheese Creations Parmesan & Mozzarella sauce.