Fill the cocktail shaker halfway with ice.
Pour the light rum, dark rum, passion fruit juice, orange juice, lime juice, simple syrup, and grenadine into the shaker.
Seal the shaker and shake vigorously for 10-15 seconds, until the ingredients are adequately blended and chilled.
Strain the cocktail into a large hurricane glass filled with fresh ice. Add an orange slice and cherry for the finishing touch.