HEAT oven to 400ºF. Place spaghetti, VELVEETA, chicken and sauce in resealable plastic bag; seal bag. Shake sealed bag and press with hands until mixture is combined. Press mixture into 9-inch pie plate or 8-inch square baking dish sprayed with cooking spray.
SPRINKLE with Parmesan.
BAKE 15 to 20 min. or until filling is heated through. Let stand 5 min. before serving.