In a medium bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Mix until well combined and crumbly.
Press the graham cracker mixture evenly into the bottom of a 9x9-inch baking dish to form the crust. Place in the freezer for 15 minutes to set.
While the crust is chilling, in a separate bowl, combine the whipped topping and vanilla extract. Gently fold in the mini marshmallows and half of the chocolate chips.
Remove the crust from the freezer and spread the marshmallow mixture evenly over the crust.
Sprinkle the remaining chocolate chips on top of the marshmallow layer.
Cover the dish with plastic wrap and freeze for at least 4 hours, or until firm.
Once frozen, cut into squares and serve immediately.