Turn on the broiler. Position rack 6 inches below the heat source. Line a baking sheet with foil.
Cut through the mangoes on either side of the pit as evenly as possible. 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. Alternately you can use a creme brulee torch to caramelize the sugar.