Does anyone know where to buy Bismarck donuts?

I love bismarck donuts, they are rectangles with white icing. THe frosting is pretty grainy similar to the frosted cinnamon rolls at Tim Hortons.They have no filling, just soft, moist donut goodness. My dad used to take me to Tasty Nu bakery (mid-Western Ontario) to get them Saturday mornings. I haven't been able to find them anywhere else. Any ideas?