Crush 20 to 25 Oreo's with rolling pin. Add 1/4 cup melted butter. Pack mixture in 13x9 inch pan and put in freezer.

Chocolate sauce:

3 squares unsweetened chocolate
1 sm. can evaporated milk
1/4 c. butter
1 c. sugar

Stir over medium heat until dissolved, then cook 10 minutes or until slightly thick. Remove from heat and add one teaspoon vanilla. Set aside until cool.

Slice 1/2 gallon vanilla ice cream (or flavor of your choice) and place on the Oreo mixture.

Next pour chocolate sauce mixture on ice cream. Return to freezer. When frozen, top with 9 ounce container of Cool Whip and serve.