Ginger Collins

2 oz gin (preferably London Dry Gin)
1 oz simple syrup
1 oz lemon juice
Dash of bitters
3 oz Barritt's Ginger Beer

- Combine all ingredients except Barritt's in a cocktail shaker and shake
- Strain into ice-filled Collins glass
- Add Barritt's Ginger Beer
- Garnish with lemon slice