To make this delicious Magic Crust Custard Pie gluten-free you can easily make a impactful change. Just substitute the all-purpose flour with your gluten-free flour blend. Make sure to choose a blend that is specifically formulated for a 1:1 replacement so that the texture and structure of the pie stay just as delightful, as the original. If your chosen blend doesn't already include xanthan gum you may want to add a pinch of it to help achieve the desired texture.