To make this Mint Chocolate Poke Cake gluten free, use a certified gluten-free chocolate cake mix, gluten-free chocolate pudding, and gluten-free mint chocolate sandwich cookies in place of Thin Mints. Also check that the chocolate chips, baking spray, and any packaged ingredients are labeled gluten free, since some processed products may contain hidden gluten or be made in shared facilities. If preparing this dessert for someone with celiac disease or severe gluten sensitivity, use clean mixing bowls, utensils, pans, and serving tools to avoid cross-contact.