I use my own gluten-free flour mix. It consists of three parts Asian white rice flour (much more finely ground that typical white rice flour) and two parts cornstarch. I make 5 lbs of this mix at a time. I use three 1-lb bags of Asian white rice flour and two 1-lb boxes of Argo cornstarch. Mix well, but gently in a very large bowl and then transfer to airtight storage containers (like large glass jars). There are many other rice-based gluten-free all-purpose flour mixes on the market that will also work in this recipe, such as Jules All-Purpose Gluten-Free Flour mix. However, this recipe will NOT work with some other all-purpose gf flour mixes like Bob’s Red Mill or Bette Hagman’s gluten-free all-purpose mix. Other flour mixes that I have not mentioned *might* work, but I can’t guarantee that. It’s also been my experience that these cookies fall apart if a baking stone is used. If your eggs are not at room temperature, the palm shortening and oil might harden and form little balls. As long as you mix your ingredients well, the cookies will still turn out fine because those little balls will melt while baking, but if your eggs are at room temperature you won't even have that concern. You may have to clean spatulas (I alternate between two) and even wipe off baking sheets of crumbs between batches. I always cool my cookies on opened paper bags to help absorb extra grease.