In a small bowl, combine the remaining ingredients and sprinkle on top of each mango slice. Place the mango slices on the prepared baking sheet. Make sure the mango halves are level so the sugar does not spill out. If you need to, use crumpled tin foil to steady the mango.
Broil for 3 minutes, or until the sugar has caramelized. Alternatively, you can use a creme brûlée torch to caramelize the sugar (which is what I did).