Skinny Frozen Peanut Butter Pies

low-fat graham cracker crumbs (about 1 cup)

light butter, melted (or regular butter)

fat-free cream cheese (or low-fat)

fat-free sweetened condensed milk

peanut butter (I use Skippy Naturals, you can use reduced-fat peanut butter if you wish)

Cool Whip Free (or you can use low-fat or sugar-free)

mini chocolate chips