COOK macaroni as directed on package. Meanwhile, cook and stir onions in Dutch oven or large deep skillet sprayed with cooking spray on medium heat 2 min. Stir in next 6 ingredients; cover. Simmer on medium-low heat 7 min., stirring occasionally.
DRAIN macaroni. Add to ingredients in Dutch oven along with the Singles pieces; cook and stir 3 min. or until Singles are melted.
SERVE topped with mozzarella and Parmesan.