Place 2 blackberries and 2 mint leaves in the bottom of a glass. Add in a dash of water and 2 tsp sugar.
Muddle everything together. If you don't have a muddler, use a spoon and just try to crush everything up in the bottom of the glass.
Add in 4 cubes of ice.
Pour a shot of BACARDÍ® rum into the glass.
Mix in 1 tbs of lime juice.
Top off the glass with Sprite (as much as needed).
Gently mix with the straw and garnish with the remaining blackberry.