Stir together ice cream and peppermint extract in a large bowl. Cover and freeze 30 minutes.
Spread about 2 tablespoons ice cream mixture onto 1 chocolate wafer; top with another wafer. Place filled sandwich on a jelly roll pan lined with wax paper. Repeat procedure with remaining ice cream mixture and cookies. Cover and freeze 30 minutes. Roll edges in crushed peppermint candies; freeze 3 hours or until firm. Wrap each sandwich in heavy-duty plastic wrap, and place in a heavy-duty zip-top plastic bag, if desired, for longer storage.