HEAT oven to 350ºF.
COOK chicken in large nonstick skillet on medium heat 5 to 6 min. or until done. Add vegetables; cook and stir 2 to 3 min. or until heated through.
ADD cooking creme and broth; cook and stir 3 min. Stir in pasta and mozzarella. Spoon into 2-qt. casserole sprayed with cooking spray; cover.
BAKE 15 min. Meanwhile, mix cracker crumbs, Parmesan and butter.
STIR casserole; top with crumb mixture. Bake, uncovered, 5 min. or until topping is golden brown.