Halve mangos and brush cut sides with melted butter. Sprinkle with sugar and grill cut side down, over medium heat for 4 to 5 minutes or until mangos are softened.
For the coulis:
Add 3 cups of raspberries to the food processor and purees until smooth. Strain through cheesecloth or strainer. In a saucepan, over low heat, add 1 to 2 tablespoons lemon juice, 6 tablespoons sugar and the raspberry puree. Stir or whisk until sugar dissolves.
Serve mangos with warm raspberry coulis, ice cream, raspberry syrup, fresh raspberries and mint.