Ingredients:
1 cube brown sugar 1/2 ounce simple syrup 12 to 15 mint leaves 3/4 ounce fresh lime juice 2 ounces white rum 2 dashes Angostura aromatic bitters Crushed ice 1 bottle club soda 1 mint sprig, for garnish

Instructions:
In Collins glass, muddle brown sugar cube and simple syrup, then add mint and lightly press to extract flavor. Add lime juice, rum and aromatic bitters. Fill glass with crushed ice and swizzle. Repack with crushed ice and top with club soda. Garnish with mint sprig.