Preheat oven to 350 degrees F. and line a 9x13 inch baking dish with parchment paper.
Place cake mix, butter and egg into medium mixing bowl. Mix until dough forms. Place cookies into bottom of dish, top with marshmallows and chocolate chips. Top with pieces of strawberry cake dough evenly over the top. Bake for 35-40 minutes until baked through. When cool spread with frosting and sprinkle with cookie crumbs. Cut into squares and serve.