Combine whiskey, lemon juice, maple syrup, cinnamon simple syrup, and bitters in a cocktail shaker.
Fill the shaker with ice.
Shake well until thoroughly chilled.
Double strain into a rocks glass filled with fresh ice.
Garnish with a cinnamon stick or dehydrated lemon wheel.
Notes
To make cinnamon simple syrup: combine 1 cup water and 1 cup sugar in a saucepan with 2 cinnamon sticks. Heat until sugar dissolves, then simmer for 5 minutes. Let cool and steep with cinnamon sticks for at least 30 minutes. Strain before use.
Adjust maple syrup and cinnamon simple syrup to your preferred sweetness.
For a richer flavor, use a good quality bourbon or rye whiskey.