How to Make It
Place cranberries in a glass container or jar; top with gin. Cover, shake gently, and let stand in a cool, dry place for at least 48 hours or up to 2 weeks.
Strain cranberries through a fine sieve over a bowl, reserving gin.
Pour gin into a large cocktail shaker or quart-sized mason jar. Add Campari, lime juice, and simple syrup. Add as much ice as possible, cover, and shake vigorously for 10 seconds. Strain about 1/4 cup into each of 8 chilled cocktail coupes or Champagne flutes; top each serving with 1/4 cup prosecco. Take an orange rind piece and, holding it by its sides, squeeze it, skin side down, over the drink to release the citrus oil. You should see the oil spray on the liquid's surface. Gently twist the peel to form a corkscrewlike curl, and drop it in as a garnish, if desired. Serve immediately.