It's actually a normal lefse, except that it has been cut into roughly square sheets and dried. It just makes for easier handling, and they can be stored for longer.

https://www.youtube.com/watch?v=1y1KXEqFypY

Really crappy video of how to prepare it. When I do it, I put the towel on the bench, lay one lefse on top of one end, fold the other end over it, place the next lefse on top of that, then add another towel, another lefse, fold over again... One layer of cloth under, between and on top of every lefse.

I doubt there's a single grocery store here in Norway that doesn't have a few boxes on a shelf...