First, make the first mojito layer
In a small bowl, add 2 packets (4 tsp.) of powdered, unflavored gelatin and 2 tbsp. of boiling water. Stir and allow to dissolve completely. Set aside.
In a cocktail shaker, add juice from 1½ limes (⅓ cup), and a bunch of mint (a nice handful). Muddle mint vigorously to really break it up and push it into the juice. Pour the juice through a strainer to separate it from the mint leaves. Set aside.
In a sauce pan over low-medium heat, combine ⅓ cup of water, ⅓ cup of white rum, ⅓ cup minty lime juice, and 1½ tbsp. of the clearer part of Cream of Coconut (it should have a thick cream on top and a clearer, viscus part on the bottom of the can. Save the creamy part for the second layer.) Slowly stir. Heat until gently simmering but not boiling, about 3-5 minutes. Add the dissolved gelatin and stir until fully dissolved, about 60 seconds. Remove from heat.
Pour mixture into molds about half-way up. Refrigerate for 3 hours.
Second, make the coconut layer
Again, in a small bowl, add 2 packets (4 tsp.) of powdered gelatin and 2 tbsp. of boiling water. Stir and allow to dissolve completely. Set aside.
In a sauce pan over low-medium heat, combine ⅓ cup of coconut rum, ⅔ cup whole milk (or coconut milk) and 1 tbsp. of the creamy part of Cream of Coconut and stir. Heat until gently simmering but not boiling, about 3-5 minutes. Add the dissolved gelatin and stir until fully dissolved, about 60 seconds. Remove from heat.
Remove your jello molds from the fridge and pour the coconut jello over the first layer. Refrigerate for at least 3 hours more.