Add the mint leaves and simple syrup to the bottom of a julep cup or sturdy glass. Gently muddle the mint to release its oils without tearing the leaves.
Stir in the lime juice.
Fill the glass generously with crushed ice.
Pour the gin over the ice and stir gently until the outside of the cup becomes frosty.
Top with additional crushed ice if needed, garnish with a fresh sprig of mint, and serve immediately.
Notes
Gently muddle the mint to release its flavor without making it bitter.
Use plenty of crushed ice to keep the cocktail icy cold.
Choose a quality gin with botanical flavors you enjoy.
Slap the mint garnish between your hands before adding it to release its aroma.
Chill your julep cup or glass before serving for an extra-refreshing drink.