Combine boiling water and gelatin together in a bowl; stir until dissolved. Mix white rum, creme de cacao, and vodka together in a bowl. Pour alcohol mixture into gelatin mixture.
Place 1 maraschino cherry into each shot glass; fill with gelatin mixture. Chill in the refrigerator until set, 8 hours to overnight. Remove from refrigerator; top with whipped cream and chocolate syrup.