To make this Black Forest Brownies Recipe gluten free, replace the regular flour with a certified gluten-free 1:1 baking flour blend. Also confirm that the cocoa powder, baking powder, chocolate chips, vanilla, and cherry pie filling are certified gluten free or free from hidden gluten-containing additives. If your gluten-free flour blend does not already contain xanthan gum, add it according to the package directions for best texture.