Chill your cocktail glass in the freezer to keep your drink cool.

In a blender, combine the frozen mango chunks and a little bit of water to help blend it smoothly. Blend until the mango is pureed.

In a cocktail shaker, combine the white rum, lime juice, simple syrup, and about 2 tablespoons of the mango puree. Add a handful of ice cubes to the shaker.

Secure the lid on the shaker and shake vigorously for about 15 seconds. Shaking not only mixes the ingredients but also chills and dilutes the drink slightly for a smoother taste.

Strain the mixture into the chilled cocktail glass. You can choose to strain it finely to remove all ice shards or leave some if you prefer a bit of texture.

Garnish with a slice of lime or a small wedge of mango on the rim of the glass for an extra touch of tropical flair.