Instructions

1. Clear a space in your refrigerator so that a large rimmed baking sheet can lay flat. Arrange 24 plastic condiment cups or shot glasses in a single layer on the baking sheet. (If your cups have lids, you can stack them covered on a small platter or smaller baking sheet instead.)
2. Place 1 (3-ounce) box lime-flavored powdered gelatin in a large heatproof measuring cup. Bring 1 cup of the water to a boil. Pour over the gelatin and whisk until the gelatin is completely dissolved, about 1 minute. Add 1/2 cup cold water and 1/2 cup cold vodka or white rum and whisk to combine.
3. Pour about 3/4 ounce of the gelatin mixture into each condiment cup or shot glass; the cup should be half-filled. Cover the cups if stacking. Carefully place the tray in the refrigerator and refrigerate until fully set, about 2 hours.
4. Meanwhile, wash the measuring cup and whisk. Repeat making the strawberry- or cherry-flavored gelatin mixture with the remaining water and vodka or white rum. Do not transfer the mixture to the cups yet — let it sit at room temperature while the first layer sets.
5. When the first layer is set, divide the strawberry- or cherry-flavored mixture evenly among the cups. Cover the cups if stacking.Refrigerate until fully set, at least 4 hours. If you’re not ready to serve yet, cover the cups — especially if you will be transporting them. When ready to serve, garnish the cups as desired.
6. To rim with sugar: Juice 1 small lime onto a small, rimmed plate. Measure 2 tablespoons coarse red, green, or white sugar sprinkles onto a separate small, rimmed plate. Dip the rim of a cup into the lime juice and let the excess drip off, then dip into the sugar.
7. To top with whipped cream and sprinkles: Top each shot with a small dollop of whipped cream and top with sprinkles.