To make these Holiday Peanut Butter Crinkles gluten free, replace the all-purpose flour with a certified gluten-free 1:1 baking flour blend that contains xanthan gum. Also verify that the baking powder, vanilla extract, powdered sugar, and peanut butter are certified gluten free if necessary for strict dietary needs. Because gluten-free dough can sometimes be slightly softer, chilling the dough briefly before rolling may help if needed.