Exotic Fruit Cocktail Shake

3 large mangoes
1/2 pound canned lychees, seeds removed
2 tablespoons confectioners' sugar
4 tablespoons lemon juice
12 large ice cubes

Slice mangoes in half. Remove the seed, then scoop out the meat. Drain the lychees. Add all ingredients in a blender. Purée to obtain a thick fruit shake. Add a little grenadine syrup, if desired. Pour into tall cocktail glasses and serve immediately.