Combine white rum, Galliano, pineapple juice, and lime juice in a cocktail shaker with ice.
Shake vigorously for 10–12 seconds until well chilled.
Strain into a chilled margarita glass.
Top with chilled Prosecco and serve immediately.
The Barracuda was created by Raffaele Casciari and is one of the official IBA cocktails; the Galliano is key to its signature vanilla-anise herbal sweetness, so don't substitute. Always add the Prosecco last and over the back of a spoon if possible to preserve the effervescence.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including Barracuda.