I've done a cursory search for maple syrup based spirits and have not found any. It appears there are liqueurs with a whiskey base and maple syrup in them but maple syrup is not the base.
I'm curious to know if any exist.
There are some companies which claim to make a maple sugar spirit. But at the same time, I can not verify if they use 100% maple sugar or not.
The really reason for people not using maple to make an alcohol spirit is the cost factor. Maple syrup is not cheap.
To make a liquor out of maple syrup, firstly you have to ferment the maple syrup (turning it into a wort), then distill said wort.
A 10kg pack of Maris Otter (common variety of malted barley used in fermentation/distillation) will cost you approximately $15 AUD; genuinely maple syrup, would cost you about $5/500mL. I don’t need to put that through a volume converter to know that it will be exponentially more expensive to source 10kg of maple syrup for the same purpose.
Nevertheless some companies seem to be distilling maple sugar into a drinkable item.
Tree Spirits Knotted Maple is probably the world's first store-sold maple syrup brandy. Bruce Olson and Steve Buchsbaum are the masterminds behind this spirited maple treat. The two of them originally opened up a winery, but as time progressed, they decided to experiment with apple cider and sap from maple trees.
Tree Spirits Knotted Maple provides a unique drinking experience and you're paying for it. A 375-milliliter bottle of Knotted Maple costs $35.99. - Alcoholic Maple Drinks
Another company is marking a new Maple Vodka, but I am unable to verify for sure if the base ingredient is in fact maple sugar.
The 80 proof Vodka is maple on the nose, clean and crisp, traditional in flavor, and finishes with a soft and delicate maple sweetness. This exclusive distillation, just shy of 1,600 bottles, will be available for sale from their tasting room and at events they attend throughout Vermont. - Caledonia Spirits to release new Vodka distilled from maple syrup on Saturday
Maple Sugar has been used for a number of years as an additive to make Maple Liqueurs, especially in Canada.
Maple liqueur refers to various alcoholic products made from maple syrup, primarily in the Northeast United States and Canada. It is most commonly made by mixing Canadian rye whiskey and Canadian maple syrup. Maple liqueur is considered an important cultural beverage in certain Canadian festivals.
In Canadian French, such a product is known as eau de vie d'érable.
Maple liqueur is not commonly found in liquor stores as it is easy to make at home. The production process is simple and does not require any special equipment. Homemade maple liqueur is both easy to make and inexpensive. It can be enjoyed on its own, in coffee, or in various different cocktails. - Maple liqueur
Knotted Maple Spirit is made from a base of Maine Maple syrup.
It seems that if you really want the real McCoy, you will have to do it in Quebec and through French websites.