To make these Ultimate Chocolate Bomb Brownies gluten free, use a certified gluten-free brownie mix and prepare it with gluten-free ingredients listed on the package. Replace Rice Krispies with certified gluten-free crispy rice cereal or gluten-free cocoa crispy cereal. Confirm that the marshmallow cream, peanut butter, chocolate chips, oil, eggs, and nonstick cooking spray are gluten free. Use clean utensils, bowls, and baking pans to avoid cross-contact with gluten-containing ingredients.