Make 2 batches at a time
Add 20 mint leaves to a blender
Add 4oz (120ml) of rum
Blend on low for 5 seconds, then high for 2 seconds
Pour into shaker tin
Add 2oz (60ml) simple syrup
Add 1.5oz (45ml) fresh lime juice
Shake and double strain into collins glasses with ice
Garnish with mint and serve!