Place all ingredients in a pot over medium-high heat on the stove. Bring to a boil, reduce the heat and simmer for 5 minutes. Remove from the heat and let cool. Strain into a clean non-reactive container (i.e. a mason jar) and keep for up to 1 week in the fridge.
Make the Cocktail:
Place all ingredients except the garnish into a cocktail shaker or mason jar. Cover tightly. Shake for 30 seconds as fast and as hard as you can. Be careful if using a mason jar that you don't break the glass with the ice.
Strain into rocks or coupe glasses and garnish with a strip of lemon zest and if using, a bourbon cherry.
When slicing the zest off your lemon, make sure you remove any white pith on the under-belly of the zest - it's very bitter and you don't want to drink that.
Recipe by She Eats at https://sheeats.ca/2016/11/christmas-cocktails-cozy-maple-whiskey-sour/