To make this Elf Spaghetti Cookie Bars Recipe gluten free, replace the fried chow mein noodles with certified gluten-free crunchy noodles, gluten-free pretzel sticks, or gluten-free crispy rice cereal. Verify that the marshmallows, marshmallow bits, chocolate fudge sauce, white chocolate chips, rainbow sprinkles, butter, and all packaged ingredients are labeled gluten free or free from gluten-containing additives. Use clean bowls, saucepans, spatulas, measuring cups, and a clean baking pan to prevent cross-contact with gluten-containing ingredients.