Can I use gluten free flour? Thx.

I don't see a reason why you couldn't substitute a quality brand gluten free flour mixture, but it might also work better if you found one of the recipes for a cream cheese pie pastry developed by one of them. Baked apple dumplings are simply apples baked in a pastry, and there are multiple versions and variations of them. And as there are no recipe police to hunt you down for making alterations, you can feel free to change one to suit your own needs and tastes.