- Muddle the fresh mint leaves and simple syrup in a julep cup to release the mint's oils.
- Fill the cup with crushed ice, packing it tightly.
- Pour the rum over the ice, filling the cup to the top.
- Stir gently to mix the ingredients and chill the drink.
- Top with more crushed ice if necessary, creating a mound on top.
- Garnish with a fresh mint sprig.
- Serve with a straw and enjoy.