Bring 1/4 cup light corn syrup, 2 tablespoons butter, 1 cup confectioners' sugar, 1/2 cup spiced rum and 1 cup mini marshmallows to a boil in a large pot over medium heat, stirring. Cook until syrupy, 5 to 10 minutes. Add 1 cup golden raisins and a pinch of salt. Remove from the heat; using a rubber spatula, stir in 12 cups popcorn until coated. Butter your hands, then shape into balls and roll in confectioners' sugar.