Decide if you're making yourself a single serving or enough to feed an army, and then choose the dish you wish to use for serving.
Dip cookie, one at a time, into the milk, pull out of mild and line the bottom of the serving dish with cookies.
Spread a layer of Cool Whip over the cookies and repeat till you have enough for your serving needs.
Cover with plastic wrap and refrigerate several hours or overnight. Serve in bowls and trust me this will go fast!! (I've experimented with several kinds of hard cookie. ie:Nutter Butters, Peanut Butter Chips A'Hoy, etc....)