Press crumbs into the bottom of your pan to form crust.
In a separate bowl, mix the ice cream with the whipped topping. I let my ice cream sit out on the counter for about 20 minutes before mixing – it is much easier if the ice cream is partially thawed. I used about 3/4 of the half gallon (since we ate a little bit the night before!), but you can use a little more or less.
Scoop the mixture into the pan, covering the crust and then freeze until ready to serve.