To make these Red Velvet Cheesecake Brownies gluten-free, replace the all-purpose flour with a certified gluten-free 1:1 baking flour blend suitable for brownies. Confirm that the dark chocolate, cream cheese, vanilla extract, red food coloring, sugar, butter, eggs, and salt are labeled gluten-free. Some chocolate, food coloring, and vanilla products may contain gluten-based additives or cross-contact warnings, so check labels carefully. Use clean mixing bowls, baking pans, parchment paper, measuring tools, spatulas, and knives to prevent gluten contamination.