Mighty-O donuts are completely vegan, and have gained a huge following in the Seattle area. They have their own donut shop location, but they ship to dozens of other coffee shops and restaurants around Seattle. You can find a list of locations that carry their donuts on their website (below).
Mighty-O specializes in cake donuts (in various flavors) that are made-from-scratch with organic ingredients. According to their website:
They contain no chemical preservatives, no hydrogenated oils (no trans fat), no coloring or artificial flavors, and no animal derived ingredients
Location: 2110 N 55th St, Seattle, WA