To make these Christmas Walnut Crinkle Cookies gluten free, replace the all-purpose flour with a certified gluten-free 1:1 baking flour blend that contains xanthan gum. Also confirm that the baking soda, vanilla extract, and any packaged ingredients are certified gluten free if necessary for strict dietary needs. Because gluten-free dough can sometimes be slightly softer, chilling the dough thoroughly before baking is especially helpful for maintaining the proper texture and spread.