Add cherries to a rocks glass or cocktail shaker and gently muddle until juices release
Pour in lemon juice and vanilla syrup and stir lightly
Add bourbon and bitters
Add ice and stir well (or shake briefly if using a shaker)
Top with additional ice if needed
Garnish and serve immediately
Notes
Do not over-muddle the cherries or the drink can become cloudy and bitterUse a smooth, mid-range bourbon with vanilla or caramel notes for best balanceAdjust vanilla syrup to taste for a drier or sweeter cocktailFresh lemon juice is essential; bottled juice will dull the flavorFrozen cherries work well—thaw slightly before muddlingFor a lighter version, top with a splash of club sodaLarge ice cubes melt slower and keep the drink balanced longer