Combine wafer crumbs, pecans, 1 cup of powdered sugar, cocoa powder, corn syrup, bourbon, and a pinch of salt in a large bowl. Add a pinch of salt. Stir until a soft dough comes together. If the dough looks too dry and crumbly, gradually add a little bit more bourbon (or some water) until it holds together. The dough shouldn’t be wet or sticky. Taste and season with a little bit more salt, if necessary. Cover and chill in the refrigerator for about 1 hour.
Pour about 1 additional cup of powdered sugar into a shallow dish. Dip the palms of your hands into the powdered sugar, scoop the dough by teaspoonfuls, and roll into round balls. Roll each ball in the powdered sugar to coat.
Store bourbon balls in an airtight container in the refrigerator until ready to serve. If desired, roll in additional powdered sugar just before serving.
Notes
To quickly crush the vanilla wafers and pecans, put them in a food processor and pulse until they're in fine crumbs.
The cookie mixture should not be sticky or wet, but it should be moist enough to hold together when rolled. If it seems too dry and crumbly, gradually add extra bourbon or water until it comes together in a workable dough.
I like the flavor of Karo light corn syrup, which has a bit of vanilla in it. That said, you can use any variety of corn syrup that you have on hand.
For a thicker coating of powdered sugar, roll the balls in confectioners' sugar a second time before serving.
A little bit of salt balances the sweetness and adds depth of flavor. Start with a pinch, and then gradually add more, if desired, to suit your taste.