To make this Apple Cream Pie Recipe gluten free, replace the all-purpose flour in both the crust and filling with a gluten-free 1:1 baking flour blend that contains xanthan gum. Confirm that the baking powder and any optional toppings are certified gluten free as well. Because gluten-free crusts can be more delicate, press the dough gently into the pan and chill it briefly before filling if needed to help it hold its shape.