Begin by slicing and juicing the limes.
Measure out the remaining ingredients needed.
If necessary, make the vanilla bean syrup ahead of time.
Add a scoop of ice to the cocktail shaker.
Add the gin, passionfruit liqueur, passionfruit juice, simple syrup, and lime juice.
Close the lid tightly and shake for at least 30 seconds.
Strain the cocktail into (preferably) chilled martini glasses.
In a small shot glass or other glass, pour an accompanying shot of sparkling wine for each cocktail.
Optionally, garnish with ½ a passionfruit or a lime wedge.
Serve cold and enjoy!