After several years of cooking gluten-free foods–not exclusively, but often–I have tested various flour combinations as a substitute for wheat flour in baking. I have also experimented with quite a number of substitutes for bread crumbs or panko. Oats, corn flakes, gluten-free bread, cornmeal and ground nuts–or a combination of these–have all gone through the unofficial Fountain Avenue Test kitchen. The one I like the best, would you believe, is Rice Chex!
Three cups of Rice Chex will crush into approximately one cup of crumbs. I typically use my mini-processor to make quick work of the grinding, although a rolling pin and a zipper-top bag works well, too. Another great option to the zipper-top bag is the actual bag the cereal comes in. Although this may pose a problem with a full box of cereal, if you are getting towards the bottom of the box, this bag makes a sturdy vehicle in which to crush your crumbs.
I have used crushed Rice Chex in place of the bread crumbs in foods like crab cakes and meatloaf (oats work well in these recipes, too), but where I really think they shine is as an exterior breading. My favorite recipe in which to use the crumbs this way is Roasted Asparagus with Panko. Dare I say I might like this dish better with the Rice Chex?!