Combine dark cherries, honey, and water in a small saucepan and place over medium heat. Cook, stirring frequently, for 4-5 minutes or until the mixture is warmed through and bubbly and the cherries release their juices.
Remove from heat and transfer the dark cherry mixture to a blender or food processor and blend until smooth. Pour into a pitcher and let cool at room temperature for 10-15 minutes.
Add lime juice and mint leaves and stir to combine. Place in the refrigerator until ready to serve.
To serve, fill four serving glasses with ice and add ¼ cup dark cherry mixture, ½ cup club soda, and one ounce gin, if using, to each glass. Stir gently to combine and serve immediately. Enjoy!