Pour 1 cup of boiling water into a large mixing bowl.
Add the Jello powder and whisk vigorously for 2-3 minutes until completely dissolved.
Pour in 1 cup of cold water and stir to combine.
Add 1 cup of your chosen vodka and stir gently to combine (avoid over-mixing to prevent foam).
Arrange 24 (2 oz) plastic shot cups on a baking sheet for stability.
Carefully pour the liquid mixture evenly into the cups, filling each about ¾ full.
Refrigerate for at least 4 hours, or overnight, until fully firm and set.
To serve, pop the shots out onto a plate, or serve directly in the cups with a dollop of whipped cream.