Showdown

Chill a cocktail coupe in the freezer to ensure it's frosty when serving.

Combine Pisco, dark crème de cacao, sweet vermouth, and freshly squeezed lemon juice in a cocktail shaker.

Add 6 drops of aged sherry vinegar and a few dashes of Angostura Cocoa bitters to the shaker.

Fill the shaker with ice and shake vigorously until well chilled.

Strain the mixture into the frozen cocktail coupe, allowing the smooth blend to flow seamlessly into the glass.