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