Back in another lifetime there were Spudnuts from a legendary franchise that produced wonderful potato-based doughnuts, mostly in the U.S. but also in Canada. Crazy Cakes in Lethbridge chose a Spudnuts location for its shop and makes Spudnuts on Thursdays. I'm in the U.S. so probably won't be making a special trip there. If you're curious about this once-very-popular item, here's more information.
1102 5th Avenue South