Beat the butter and sugar in a large bowl until light and fluffy.
In the top of a double boiler, melt the chocolate. Add to the butter-sugar mixture and beat thoroughly. Add the eggs one at a time, beating well after each egg, until well blended. Fold in the peppermint and vanilla.
Line the pie tin with the vanilla wafer crumbs (buttering the pie tin makes them stick to the side a little better). Pour in the filling. Refrigerate for two hours.