Rim a rocks glass with cinnamon sugar, if desired.
In a cocktail shaker filled with ice, combine bourbon, apple cider, lemon juice, and simple syrup.
Shake well and strain into the prepared rocks glass.
Top with club soda and gently stir.
Garnish with an apple slice, if using.
Serve and enjoy!
Notes
For a spicier twist, add a dash of bitters to the cocktail shaker before shaking.If you don't have a cocktail shaker, you can use a mason jar with a lid.Substitute maple syrup for the simple syrup for a richer flavor.For a non-alcoholic version, omit the bourbon and add an extra 1/2 ounce of simple syrup.