In a small bowl, pour ½ cup of whisky over the pecans. Cover and soak the pecans overnight.
Spread out the pecans on a cookie sheet and bake at 350° F (180°C) until lightly toasted - approximately 15 minutes. Let them cool and then chop finely.
Process the vanilla wafers in a food processor until they are crumbled. Add in the cocoa, powdered sugar, light corn syrup, ¼ cup whisky, and cooled pecans. Pulse until combined.
Use a cookie scoop or your hands to measure out the balls to not more than 1 inch each. Roll them to tight balls and shape them into evenly round balls.
Roll into chocolate jimmies, nuts, cocoa powder or other sprinkles. If the balls are a little "wet" feeling, refrigerate to dry.