I recall not if this doughnut was vegan, gluten-free or what but it matters little to me since it was so tasty. Maybe a little too much sugar and cinnamon for my taste, but similar to the tasty donuts over at the carpe donut truck. They have tons of different flavors too. I just looked it up and they are vegan.
Cinnamon Snail, 5th Avenue between 21st and 22nd Streets, New York, NY 10010