Preheat oven to 350 deg. Line a 9x13 pan with foil & coat w/ spray. Mix cookie mix, butter & egg with paddle attachment on stand mixer till dough forms.
Press 1/2 of dough into pan. Top w/ condensed milk, keeping from edges of the pan. Sprinkle evenly w/ chips. Drop remaining dough by spoonfuls & spread them slightly using your hands. It may be easier to spray your hands first. Sprinkle w/ cinnamon-sugar topping over bars.
Bake 25-35 min or until bars start to turn golden brown. Center might be still a little jiggly, but it will firm more as it cools.they are easier to slice if you let them cool completely before slicing.