Traditionally crumble crust is made with white flour. This obviously is not the healthiest option, although delicious. I wanted to create something that was just as delicious but contained a nutritional punch. Ergo, oat flour. Most people, including myself, don’t buy oat flour. It’s too expensive and why when you can make it yourself for so cheap. Blend those suckers up! You can use quick oats or old fashioned rolled oats, (that’s what I used).