Combine crushed cookies, nuts, the 1 cup powdered sugar, corn syrup, liqueur, and butter in a mixing bowl; stir with a wooden spoon until well-mixed. Shape into 1-inch balls.
Roll balls in the 1/3 cup sifted powdered sugar (combined with edible glitter, if desired); cover. Let stand 2 hours. Before serving, roll again in powdered sugar. Chill up to 2 days or freeze up to 3 months. Makes 40 balls.