Add the apple juice and cranberry juice to a saucepan.
Add in the sugar and stir. If you are using superfine sugar, it should dissolve pretty quickly.
Sprinkle the gelatin powder on top of the liquid in the saucepan. Then, let everything sit for about 5 minutes so the gelatin can bloom.
Put the saucepan on the stove and heat it on very low heat while stirring. This only needs to get up to around 140°-160℉. No need to boil!
Once the gelatin is all melted, take the saucepan off the heat and let it cool down to room temperature.
Stir in the vodka and triple sec.
(Optional) Transfer the liquid to a squeeze bottle or a Jellinator.
Fill up your serving cups with the liquid.
Put the filled cups in the fridge until they're set. This could take around 1 to 3 hours depending on your fridge.
Right before serving, add a sugared cranberry and a little piece of fresh rosemary as a garnish (optional).
Serve and enjoy! If you made a more firm set (see Notes), you may want to serve it along with a spoon.
Notes
Powdered gelatin: the amount called for will give you a softer set than regular jello to make it easier to get out of the little cups. If you like it even softer, use only one packet (2½ teaspoons/7 grams). If you like it more firm, or you want to set it in a pan and cut it into squares, use two packets (5 teaspoons/14 grams). The liquid amounts will stay the same.
Cranberry Jello: if you want to use a pack of cranberry flavored jello, you can substitute that in by taking out the plain gelatin and the sugar. You can use the whole 3 ounce packet of jello for a firm set, or use about three quarters of a pack (2¼ ounces if you have a kitchen scale) to get a softer set.
Sugared Cranberries: to make these, soak cranberries in maple syrup overnight. Strain out the syrup and roll them in sugar.