This drink is quite old, and quite easy to make. A "julep" originally meant a sweet drink used to deliver medicine. One of the earliest references dates back to 1784. In 1803, John Davis describes it as "a dram of spirituous liquor that has mint steeped in it, taken by Virginians of a morning." So it's origin is generally attributed to the Southern US. And, while it is generally made with Bourbon whiskey, it has been made with gin and brandy as well. So feel free to experiment!
60 mL Beat 3 Reserve Whiskey
4 mint leaves
1 tsp Powdered Sugar
2 tsp water
In a highball glass gently muddle the mint, sugar and water. Fill the glass with cracked ice, add Beat 3 Reserve, and stir well until the glass is well frosted. Garnish with mint.