Add the chocolate wafers to the bowl of a food processor, and pulverize into fine crumbs. Add the crumbs to a large bowl.
Then process the pecans with the powdered sugar and cocoa powder until finely ground. Add the butter and corn syrup. Process until well combined. Scrape the mixture into the bowl with the wafer crumbs. Stir until evenly incorporated.
Add the bourbon to the cookie crumb mixture. With a wooden spoon, stir until the mixture is uniform in consistency and begins to clean the sides of the bowl. Add a little more bourbon if the mixture is too dry to hold together. Let the mixture sit, covered, for 30 minutes to absorb the bourbon.
Scoop out level tablespoons of the mixture and press and roll between the palms of your hands to shape into 1¼-inch balls.
Place the granulated sugar in a small bowl. Add one ball at a time, and roll it around in the sugar. The coating is most attractive when the balls are dipped three times. Re-dip after the sugar starts to disappear.
Place the balls in a paper towel or parchment-lined airtight container at room temperature- serve within 6 weeks.
Notes
To skip the bourbon: 2 tablespoons of water and 1/2 tablespoon vanilla extract can be substituted for the bourbon.