In the bowl of a food processor, combine wafer cookies and walnuts. Process until finely ground. Set aside.

In a large bowl, sift together powdered sugar, salt and allspice.

Stir in rum and corn syrup.

Add cookie and nut mixture, stir well to combine.

Chill mixture for 30 minutes.

Scoop out tablespoon portions using small cookie scoop, roll into balls and return to the fridge while you melt your chocolate.

Gently melt 2/3 of your chocolate either in 30 second bursts in the microwave until mostly melted, stirring after each time (it will continue to melt as you stir) OR melting in a small bowl set over a pot of simmering water.

When the chocolate is melted and hot, remove from the heat and add the remainder of your chocolate. Stir with a rubber spatula, making sure to scrape the sides and bottom, for about 4 - 6 minutes. The chocolate should be cool. Lightly touch the spatula with the chocolate on it to the area just below your bottom lip. If it doesn't feel very warm anymore, you're ready to dip! If it does, keep stirring for another minute or two to cool the chocolate.

Using a skewer or fork, dip each rum ball in chocolate and gently drag the bottom of the rum ball against the side of the bowl to remove excess chocolate. This will prevent your rum balls from having a "foot" or a pool of melted chocolate on the bottom.

Place chocolate covered rum balls on a parchment-lined baking sheet as they are dipped. Place walnut pieces on top, if using. Leave at room temperature for the chocolate to set, then place in refrigerator, if needed.