Prepare the glass first. On a small plate, combine low carb granular sweetener (eg Lankanto) and ground cinnamon.
Pour a little of the syrup onto a paper towel. Wipe it around the rim of a martini glass. Then place the inverted glass into the cinnamon mixture, carefully turning it to ensure the whole rim is coated.
To make the cocktail, add heavy cream, vodka, and the maple syrup to a cocktail shaker.
Shake well, then pour over ice into the prepared glass. Garnish with a cinnamon stick.