Crush the vanilla wafers. Do this by placing them in a food processor and pulsing until they are even sized fine crumbs. If you don’t have a food processor, place the cookies in a zip-top bag (leave a small opening in the top of the bag so that the bag doesn’t burst open and shower your kitchen in cookie crumbs) and crush them with a rolling pin, a flat meat tenderizer, or your fist until they are fine crumbs.
Place the crumbs in a medium bowl. Add the chopped nuts, sugar, and cocoa, and mix well.
Combine the syrup and rum or peppermint schnapps and peppermint extract in a small bowl, and add to the crumb mixture. Mix well.
Using a small cookie dough scoop or a tablespoon, scoop out portions of the dough mixture and press into balls. Using your hands, roll the balls in the confectioners' sugar, coating evenly.
The powdered sugar will harden and help keep the dough in the shape that you want.
Once the rum balls have hardened, dip them in melted chocolate and decorate with crushed peppermints.