I tested these cookies with several different gluten free flour blends.  You definitely want to use a blend that is designed to be a 1:1 replacement for traditional all-purpose flour. I found Bob's Red Mill 1:1 Gluten Free Baking Flour to be the best. It's fine texture lent the best results for texture.  I also tested these Lemon Crinkle Cookies with Krusteaz Gluten Free All Purpose Flour. They turned out great, but we still preferred the Bob's Red Mill version.  I do not recommend Trader Joe's Gluten Free All Purpose Flour. The cookies using the Trader Joe's flour were definitely grittier and crumbled easily.