HEAT oven to 375ºF.
COOK pasta as directed on package, adding spinach to the boiling water the last minute.
COOK and stir chicken and basil in large nonstick skillet sprayed with cooking spray on medium-high heat 3 min. Stir in spaghetti sauce and tomatoes; bring to boil. Simmer on low heat 3 min. or until chicken is done. Stir in Neufchatel.
DRAIN pasta mixture; return to pan. Stir in chicken mixture and 1/2 cup mozzarella. Spoon into 2-qt. casserole or 8-inch square baking dish.
BAKE 20 min.; top with remaining cheeses. Bake 3 min. or until mozzarella is melted.