If I was a Vegan or a Celiac I would frequent One Lucky Duck. The desserts just taste "healthy". They are slightly pricey, but it is something you might expect to find where natural, fresh, non-processed ingredients are used. I bought a few pieces to bring back to the office. I do not work with any vegans or celiacs. The biggest hit was the Chocolate Almond Square, it tasted like an Almond Joy.  Their Gingersnap Cookie and the Mallomar were runner ups.  If you are looking for a spot for healthy treats, this is your best option in NYC.
http://bit.ly/oneluckyduck