Crush all Oreos and Mix with melted butter or margarine in large bowl
Press the Oreo mixture into the bottom of a 9 x 13 baking dish and freeze
Slice ice cream into slivers and spread over the top of the cold Oreo crust
Spread softened ice cream over cold crust and freeze until set
Combine powdered sugar, chocolate chips, evaporated milk, 1/2 cup Margarine or butter, and vanilla in sauce pan on stove
Bring ingredients to a boil over medium heat and boil 7 minutes, stirring constantly
Remove chocolate mixture from heat and cool completely (You can cool in a separate bowl over ice to help cool more quickly if you'd like!)
Pour chocolate sauce over ice cream and freeze until set - then enjoy!