Step 1: In a large bowl, combine the finely crushed vanilla wafers, 1 cup confectioners' sugar, cocoa powder, and salt. Whisk together until well mixed.
Step 2: In a separate small bowl, whisk together the melted butter, dark rum, and vanilla extract until fully combined.
Step 3: Pour the wet ingredients into the dry ingredients. Mix thoroughly with a spoon or your hands until a thick, moist, and cohesive mixture forms. It should be firm enough to roll.
Step 4: Cover the bowl with plastic wrap and refrigerate the mixture for at least 30 minutes (or up to 2 hours) to firm up, making it easier to handle and allowing the flavors to meld.
Step 5: Place extra confectioners' sugar (or other desired coatings like cocoa powder, sprinkles, or finely chopped nuts/coconut) in a shallow dish.
Step 6: Remove the chilled mixture from the refrigerator. Roll spoonfuls of the mixture (about 1-inch diameter) into smooth balls. If the mixture is too sticky, slightly dampen your hands or dust them with a little confectioners' sugar.
Step 7: Roll each rum ball in the confectioners' sugar (or chosen coating) until evenly coated. Place them on a baking sheet lined with parchment paper.
Step 8: Store the Easy, Festive (and Boozy!) Rum Balls Recipe in an airtight container at room temperature for up to 1 week, or in the refrigerator for up to 3 weeks. The flavor actually improves over time as the rum infuses further!