0.75 ounces simple syrup – 1:1 (equal parts sugar and water)
1 ounce egg white – for silky foam (optional)
1.5 cups ice cubes – for shaking
lemon peel – wide strip; expressed over drink (for garnish)
Angostura bitters – dashed on top (for garnish)
cocktail cherry – for garnish
Instructions
Chill a coupe or small rocks glass in the freezer until frosty, about 5 minutes.
Add the bourbon, lemon juice, simple syrup, and egg white (if using) to a cocktail shaker and dry shake (no ice) until foamy, about 15 seconds.
Add the ice cubes to the shaker, seal, and shake hard until the shaker is icy-cold and frosty, 12–15 seconds.
Double strain immediately into the chilled glass to catch ice shards; the drink should pour with a creamy head.
Express the lemon peel over the surface and drop it in; dot the foam with 2–3 dashes Angostura bitters and add a cocktail cherry. Serve immediately while cold.