Preheat the oven to 350 degrees and spray an 8” square baking pan with non-stick cooking spray. Using an electric hand mixer, blend butter and egg together until smooth, then add dry cookie mix and crushed graham crackers.
Mix until a dough forms then add marshmallows and fully incorporate into the dough. Press dough evenly into prepared pan and top with chocolate chips.
Bake 25-30 minutes or until the top is golden and a toothpick inserted in the center comes out clean. Remove from oven and cool to room temperature on a wire rack. Cut into 16 bars.