To make these S’More Granola Bars gluten-free, substitute the all-purpose flour with a 1:1 gluten-free flour blend and use certified gluten-free oats. Replace the graham cracker crumbs with gluten-free graham-style crumbs or crushed gluten-free digestive biscuits. Ensure that all remaining ingredients, particularly chocolate chips and marshmallows, are labeled gluten-free and processed in a certified gluten-free facility to avoid cross-contamination.