To make this Polish Pierogi Recipe gluten free, replace the all-purpose flour with a reliable gluten-free all-purpose flour blend that is designed for dough or dumplings. Because gluten-free dough can be more delicate, you may need to add a small amount of xanthan gum if your flour blend does not already include it. Roll the dough gently and avoid overfilling the pierogi so they remain easier to seal. Also confirm that the shredded cheese, baking powder, and any serving ingredients such as sour cream are labeled gluten free, since ingredient formulations can vary by brand. A lightly floured surface using gluten-free flour will also help with handling the dough more easily.