Chill a Collins or highball glass by filling it with ice and setting aside. If using whole (not pasteurized) egg white, ensure eggs are fresh and handled hygienically.

Dry shake

In a cocktail shaker, add amaretto, pistachio liqueur (or pistachio orgeat), crème de cacao, maraschino liqueur, fresh lemon juice, optional simple syrup, and the egg white. Do not add ice yet. Seal the shaker and dry shake vigorously for 15–20 seconds to emulsify the egg white and incorporate air for a foamy texture.

Wet shake

Open the shaker, add a generous hand of ice, reseal, and shake hard for another 10–15 seconds until the shaker is cold to the touch (this chills and dilutes the drink).

Strain and top

Discard the ice from the chilled glass and double-strain the shaken mixture into the glass to remove any small ice shards and ensure a silky texture. Gently top the drink with approximately 2 oz club soda to create a light fizz and a distinct foam crown.

Garnish

Carefully place a maraschino cherry on the foam. If desired, sprinkle 1 teaspoon of crushed pistachios around the edge of the foam (avoid sinking into the drink to keep foam intact).

Serve

Serve immediately with a straw or stirrer on the side. Advise guests that the drink contains nuts and egg.