2 oz whiskey (bourbon or rye)
3/4 oz fresh lemon juice
1/2 to 3/4 oz simple syrup (to taste) or 1/2 oz sugar syrup
1 egg white (optional for foam) or 1/2 oz aquafaba (optional)
Ice
Add whiskey, lemon juice, and simple syrup to a shaker
If using egg white/aquafaba, add it to the shaker
Dry shake (no ice) for 10–15 seconds if using egg white/aquafaba
Add ice to the shaker
Shake vigorously for 15–20 seconds
Strain into a chilled coupe or rocks glass
If using egg white/aquafaba, garnish with a few drops of lemon bitters or a lemon twist (optional)