I would not suggest using any other flours in this recipe. I truly believe you will be left with a super dense roll if you don't use cassava flour. It's truly worth the splurge in my mind. And when you've been eating gluten free baking for as long as I have you know when you've stumbled upon a good thing. You can get cassava flour at most natural health food stores. I've also lucked out at The Real Canadian Superstore in the natural aisle. It's the best price I've seen for it (as it is a pricier flour).