Bring mango, sugar, water & cilantro to a low boil. Simmer about 6 minutes stirring occasionally. Careful transfer to a blender & liquefy. Refrigerate until chilled, about 30 minutes.
Pour 1/2 cup mango purée into an ice filled martini shaker. Add the vodka & lime juice. Shake well. Strain into a chilled martini glass. Top with a fresh cilantro spring.
Mango purée makes 3 cocktails