Step 1 Add all ingredients into a cocktail shaker and emulsify with a milk frother or dry shake without ice. Step 2 Add as much ice as you can fit into the shaker. Shake very hard and fine strain into a chilled wine or sour glass. Step 3 With one confident motion, swipe your angostura bitters across the surface of the cocktail to create the cross. Be careful as Angostura stains!