To make these Ginger Cookies Sandwiches gluten-free, replace the unbleached all-purpose flour with a certified gluten-free 1:1 baking flour blend suitable for cookies. Confirm that the molasses, powdered sugar, cream cheese, vanilla extract, baking soda, spices, sugars, butter, egg, and salt are labeled gluten-free. Some spice blends, extracts, and powdered sugars may contain additives or cross-contact warnings, so check labels carefully. Use clean mixing bowls, baking sheets, parchment paper, measuring tools, spatulas, and cooling racks to prevent gluten contamination.