Mistaken Ray

Combine the light rum, gin, lime juice, honey syrup, passion fruit syrup, pineapple juice, bitters, and falernum in a blender. Blend briefly to mix the ingredients without over-aerating.

Pour the mixture into a highball glass filled with crushed ice.

Gently stir in the soda water to integrate it into the cocktail.

Carefully float the Jamaican rum on top for a layered effect.