Ingredients

• Ice, preferably crushed
• 1 1/2 ounces dark rum
• 1 1/2 ounces gold rum
• 1 1/2 ounces freshly squeezed or store-bought 100% grapefruit juice
• 1 ounce 151-proof Demerara rum
• 1 ounce 100% pineapple juice
• 3/4 ounce freshly squeezed lime juice (1/2 medium lime)
• 1/2 ounce grenadine
• 1/2 ounce Simple Syrup
• 1/8 teaspoon ground cinnamon
• 1 dash Angostura bitters

For garnish

• 1 to 2 sprigs fresh mint
• 1 slice grapefruit
• 1 maraschino or cocktail cherry (optional)

1. Fill a highball glass halfway with ice. 
2. Place 1 1/2 ounces dark rum, 1 1/2 ounces gold rum, 1 1/2 ounces grapefruit juice, 1 ounce 151-proof Demerara rum, 1 ounce pineapple juice, 3/4 ounce lime juice, 1/2 ounce grenadine, 1/2 ounce simple syrup, 1/8 teaspoon ground cinnamon, and 1 dash Angostura bitters in a cocktail shaker. Fill the cocktail shaker halfway with ice, seal the shaker, and shake vigorously until the outside of the shaker is frosty, about 20 seconds.
3. Pour through a strainer into the glass. Garnish with 1 to 2 fresh mint sprigs, 1 grapefruit slice (squeeze the juice from the grapefruit into the drink first if desired), and 1 maraschino cherry if using.