Fill a glass with ice. Add the bourbon, bitters, cider and caramel to a cocktail shaker and shake for a few seconds until combined. Pour over ice and garnish with green apple slices.

Combine all the ingredients in a saucepan over medium-low heat. Whisk to combine, then cook and stir until the mixture is bubbling. Cook for 5 to 6 minutes until it slightly thickens and is smooth. Remove from heat and let it cool to room temperature – it will thicken as it cools. Store in a sealed jar in the fridge.