I'm making David Lebovitz's coconut macaroons, which calls for 1/4 cup of flour. I've made these cookies at least a dozen times with the ingredients called for, but this time I would like to make them for someone who is allergic to gluten. I have rice flour on hand, but I'm not sure if it would adversely effect the recipe to the point it not being worthwhile. Also, would it be a 1 to 1 substitution? Since it's only a quarter cup, I'm willing to give it a try in any case. Any suggestions are appreciated.