Run a lemon wedge around the rim of 4 x 2.5-ounce shot glasses. Dip dampened rims into colored sanding sugar at a 45-degree angle.
Continue rotating and dipping until the entirety of each rim is coated with the sugar.
Fill a cocktail shaker about halfway with ice. Add black cherry rum, sour apple schnapps and sweet and sour mix. Shake until chilled throughout.
Carefully pour into the rimmed glasses and garnish with SweeTarts candies if liked.
Notes
Chill your glasses: Pop shot glasses in the freezer before serving for an extra crisp drink. Shake vigorously: A good shake with plenty of ice ensures the drink is cold and well blended. Make a batch: Scale up the ingredients and use a pitcher or large shaker if you're serving a crowd.