Measure the bourbon and place it into a cocktail shaker. Add the pumpkin puree, Keto maple syrup, pumpkin pie spice, vanilla extract, Angostura bitters, and ice to the shaker. Securely fix the cap and shake hard for 10 seconds.
Step 2
Add blocks of ice to a lowball glass. Pour the cocktail into the glass. Top with more ice if necessary. Garnish with rosemary sprigs, cinnamon sticks, or orange peel (optional).