Prepare cake mix according to the directions on the package, substituting iced coffee for the water. Cool completely; loosely crumble and set aside.
In a medium bowl, empty pudding mix. Pour in milk and ½ cup iced coffee and whisk constantly for three minutes. Place bowl in the fridge and allow to chill for at least 30 minutes.
Once cake has cooled and pudding has thickened, assemble your parfaits. Alternate layers of cake, pudding, and whipped topping; repeat. Garnish rim of serving dish with chocolate sandwich cookies, if desired.
Recipe by Views From the Ville at http://viewsfromtheville.com/2013/02/28/dessert-iced-coffee-recipe/