Cut the passion fruit in half and scoop out the pulp into a measuring cup. If the pulp yields less than about 0.5–1 oz, you can supplement with 0.5 oz passion fruit purée or additional liqueur.

Combine ingredients

In a cocktail shaker add the vanilla vodka, passion fruit liqueur, fresh passion fruit pulp, fresh lime juice, and simple syrup. If using egg white for a silkier texture, add it now.

Dry shake

Seal the shaker and shake vigorously without ice for 10–15 seconds (dry shake) if you added egg white. This helps emulsify and produce a frothy texture.

Shake with ice

Open the shaker, add ice (about 4 oz or enough to fill half the shaker), close and shake hard for 10–15 seconds until the shaker is very cold to the touch and well-chilled.

Double strain and serve

Double strain the cocktail into a chilled coupe or martini glass using a fine-mesh strainer to catch seeds and ice shards. The drink should be bright, slightly pulpy, and topped with a thin foam if egg white was used.

Serve / Garnish

Pour the chilled Prosecco (about 3 oz) into a small shot glass or flute and serve it alongside the cocktail. The classic presentation lets the drinker sip the sparkling wine between sips of the passion fruit cocktail or pour a splash into the cocktail to taste.

Garnish the cocktail with the reserved half passion fruit (place it on the rim or float the pulp), and add a lime wheel if desired.