It's worth seeking out high-quality maraschino cherries, such as those from the brand Tillen Farms -- they're free of artificial color.
Combine bourbon, lime juice, sugar, marmalade, and bitters in a pitcher. Stir vigorously until sugar and marmalade are dissolved.
Fill rocks glasses with crushed ice, top with bourbon mixture, and serve each with a maraschino cherry and a drizzle of cherry liquid.
