1. Pour water to a depth of 1 inch into bottom of a double boiler over medium heat; bring to a boil. Reduce heat, and simmer; place cream and eggs in top of double boiler over simmering water. Cook, stirring constantly, 4 minutes or until mixture thickens and reaches 160°. Remove from heat, and transfer to a large bowl.
2. Stir in coconut milk and next 5 ingredients. Cover and chill 3 hours. Garnish, if desired.
Make It Dessert! Leftovers aren't likely, but if you have them, turn them into a delicious frozen treat. Pour mixture into an ice cream maker, and chill it according to manufacturer's directions. The results will be slightly softer than traditional ice cream because of the rum. Try it drizzled with caramel sauce.