Start by placing the cold apple cider and unflavored gelatin in a medium mixing bowl. Lightly stir the mixture just until all the gelatin powder gets covered with liquid. You don't want to overstir at this point or you might create lumps in your finished shots.

Let the gelatin mixture sit undisturbed for about 3 minutes. This blooming time allows the gelatin to absorb the liquid and soften, which helps it dissolve smoothly when you add the hot liquid. You'll notice the mixture will look thick and slightly cloudy during this resting period.

Pour the hot apple cider over the gelatin mixture and stir gently but thoroughly until the gelatin is completely dissolved. Keep stirring until you can't see any remaining gelatin particles and the mixture is smooth and uniform. If you notice any lumps, pour the mixture through a fine mesh sieve to remove them without ruining your shots.

Add the Fireball whiskey to the bowl and stir it in completely. The alcohol will give these shots their signature kick while the cinnamon flavor complements the apple cider beautifully. Make sure everything is well combined before moving to the next step.

Fill your shot cups about ¾ of the way full with the gelatin mixture. Leaving a little room at the top allows space for the whipped cream topping if you're adding garnishes. Place the filled cups in the refrigerator to chill for 2 hours or until fully set.

Top each shot with a dollop of whipped cream, a sprinkle of cinnamon sugar, and a thin red apple slice just before serving. These garnishes are optional but they elevate the presentation and add extra flavor and texture to each bite.