To make these White Chocolate Chip Cookies gluten-free, replace the all-purpose flour with a certified gluten-free 1:1 baking flour blend. Confirm that the white chocolate chips, baking soda, baking powder, vanilla extract, sugars, salt, and butter are labeled gluten-free and free from cross-contact. Use clean mixing bowls, measuring tools, baking sheets, parchment paper, spatulas, and cooling racks to prevent gluten contamination.