Place ice cream in a large bowl and let stand at room temperature until very soft. Break the Butterfinger and Heath Bar into pieces and mix into ice cream. Spoon the ice cream into the piecrust. Sprinkle cookies over the ice cream and top with M&Ms. Freeze the pie until ice cream is very firm, at least 2 hours. Cut into wedges and serve.
Copyright 2002, Janette Barber and Christina Deyo, all rights reserved