For the rim, place the cane sugar and 1 tsp pumpkin spice in a shallow dish. Mix around with a spoon so they are well incorporated. Use a paper towel or a cloth and dip it in some extra maple syrup. Hold your cocktail glass upside down and run the paper towel around the edge of the glass to coat it. Then, still holding the glass upside down, gently dip the rim into the sugar mixture to coat. Do a few circle motions with the glass without letting it scrape the bottom of the dish to fully coat. Set the glass aside to allow the rim to set and dry while you prepare the cocktail.
In the bottom of your cocktail shaker or a separate glass, mix the pumpkin puree, apple cider and pumpkin spice well with a spoon or whisk. Mix until the pumpkin is dissolved into the liquid. There will be some bits of pumpkin spice remaining and that's okay.
Fill the cocktail shaker with ice and pour in the pumpkin mixture if it's in a separate glass. Add the maple syrup, bourbon, and two dashes of bitters. Place the other half of the cocktail shaker on top and shake vigorously for 10 - 15 seconds.
Add a large ice cube to your cocktail glass and pour the cocktail through a drink strainer and over the ice. If you don't have a drink strainer, use the side of the cocktail shaker to hold the ice while you pour. Garnish with a cinnamon stick and a thinly sliced apple slice if desired and enjoy!