Copycat version of Dairy Queen's popular Buster Bars.
Line the bottom of 9x13-inch dish with crushed Oreos (I like to use a tall foil pan, so I can just toss it when done). Spread softened ice cream over Oreos. Place the dish in the freezer and allow time for the ice cream to freeze again (1 to 2 hours).
Spread fudge sauce on top of the vanilla ice cream (if it's too thick, put it in the microwave for just about 10 seconds to soften a bit). Sprinkle peanuts on top of the fudge, then the Cool Whip over the peanuts. Freeze again.
Cut into squares, and serve with additional hot fudge and peanuts- if desired.