I have been making this one for years. It is made in stages so you have to plan ahead a bit, but it is soooooooo worth it!
1 package Oreo cookies
1/2 gallon chocolate-chip mint ice cream
1 tub of Cool Whip
1 jar of hot fudge
Soften ice cream, then mix in a large bowl with Cool Whip. Set aside.
Place 3/4 of the Oreos in a sealed plastic bag. Crush with a rolling pin. Spread most of the crushed Oreos in the bottom of a 9 x 13 pan, setting a little bit aside for garnish later. Gently spread a layer of the ice cream/Cool Whip mixture on top of it. Freeze.
Once frozen, remove lid from the hot fudge and microwave for 1 minute. Spread hot fudge carefully on top of dessert. Re-freeze.
Once hot fudge has cooled enough, spread another layer of the ice cream/Cool Whip mixture on top. Sprinkle with a little crushed Oreo for garnish. I like to sink a few whole Oreos half way into the ice cream around the edge for additional decoration.