1.5 oz. aged Jamaican rum (like Denizen Merchant’s Reserve)
1.5 oz. Puerto Rican rum (like Bacardi 8 yr)
1 oz. 151-proof rum (like Hamilton or Lemon Hart)
1/2 oz. falernum
1/2 oz. Don’s Mix (2:1 white grapefruit juice to cinnamon syrup)
3/4 oz. lime juice
1 dash Angostura bitters
1/8 tsp Absinthe, Herbsaint, or Pernod
1/2 oz. grenadine
Combine all ingredients in a shaker tin. Add ice. Shake heavily and then strain into a Collins glass or tiki mug with ice.