1Heat oven to 350°F. In medium bowl, stir cookie mix, butter, vanilla and egg until soft dough forms. Divide dough in half (about 2 cups in each half). With half of the dough, shape, bake and cool cookies as directed on box. Reserve for another use.
2Meanwhile, stir cocoa into remaining half of dough. Crumble dough onto cookie sheet with sides. Bake 8 to 10 minutes until dough is baked through and just starting to turn light brown. Cool 5 minutes; toss with spatula to make crumbs.
3In ungreased 9-inch glass pie plate, press 1 cup of the cookie crumbs. Place small scoops of ice cream in single layer over crust; sprinkle with 3/4 cup of the crumbs. Top with remaining ice cream and crumbs. Cover; freeze at least 2 hours.
4In small microwavable bowl, microwave chocolate fudge topping on High 10 to 15 seconds. Drizzle topping over pie just before serving.