To make these Fluffy Banana Cookies gluten free, replace the all-purpose flour with a 1:1 gluten-free flour blend designed for baking. Make sure the blend contains xanthan gum, or add it if needed according to the package directions. Check that your baking soda, spices, and chocolate chips if using are certified gluten free to avoid cross-contact. Because gluten-free dough can sometimes be softer or more delicate, let the batter rest for 5 to 10 minutes before scooping to help the flour hydrate properly. Bake as directed, and allow the cookies to cool fully so they hold their shape well.