Mix chocolate cookie crumbs and melted butter. Pat into the bottom and sides of 9- or 10-inch pie dish. Refrigerate at least one hour.
In a saucepan, melt marshmallows in milk over medium heat. Remove from heat and cool to room temperature. Add the creme de menthe and creme de cacao and mix well. Fold in the whipped cream. Pour the filling into the chilled pie shell and freeze until firm, at least 4 hours.
Slice the pie and add an additional dollop of whipped cream for serving, if desired.
