Fudge: In a saucepan over medium heat, add butter, evaporated milk, powdered sugar, and chocolate chips. Stir frequently until all is melted and smooth. Bring to a boil and continue to stir constantly for 8 minutes.
Remove from heat and stir in vanilla. Set aside and let sit for 45-60 minutes, until cool.
Crust: In a food processor (or blender), place 36 whole Oreo cookies and pulse until finely crushed. Remove 1/4 cup to be used as topping. Add the melted butter to the remaining crushed cookies and pulse again until well combined.
Pour Oreo mixture into the bottom of a 9×13 baking dish. Spread out and press down to form the crust. Place the baking dish in the freezer to chill while the fudge is cooling.
Layers: Once fudge sauce is cooled, remove the baking dish from the freezer. Spoon softened ice cream on top of the cookie crust. Smooth out the ice cream to form an even layer over the crust. Sprinkle the chopped peanuts over the ice cream layer.
Top the peanut layer with the fudge sauce, spreading out to form another even layer. Cover and freeze for about an hour, until set.
Remove from the freezer and layer the Cool Whip over the fudge layer. Sprinkle with the remaining crushed Oreos. Place back in the freezer until ready to serve!