1 cup boiling water
1 (6 ounce) box strawberry-banana-flavored Jell-O® mix
1 cup coconut-flavored rum (such as Malibu®)
Arrange 12 2-ounce plastic cups on a baking sheet.
Slowly pour boiling water over gelatin mix in a bowl while whisking. Continue whisking while streaming rum into the gelatin mixture. Pour mixture into plastic cups.
Refrigerate until set, 8 hours to overnight.