We haven't tested substituting this with Bob's Red Mill 1:1 gluten free all purpose flour, so we can't answer this with certainty. If you'd like to try it yourself, let us know how it goes! If you do try it, we'd suggest starting out with roughly 2 cups gluten free plain flour, then adding more slowly as needed. The crust texture needs to be sandy-like, that comes together when pressed together gently. This will give us that nice crumbly, biscuit base.