From: Art of Gluten-Free Baking (http://artofglutenfreebaking.com)
-adapted from Southern Pies, by Nancie McDermott
Make crust dough and use it to line a 9 inch/22 cm pie pan. Crimp the edges. Cover with plastic wrap and place in refrigerator while you make the filling.
Preheat oven to 350 degrees F/180 degrees C/Gas Mark 4
Make the filling
Remove dough-lined pan from fridge. Scatter peaches slices along the bottom of the crust.
Pour filling evenly over the peaches.
Place pie on center shelf of oven and bake at 350 degrees F until custard filling is set and the crust is nicely browned, about 50-55 minutes.
Make the topping
When pie has cooked, remove from oven and scatter the topping evenly over the filling. Return to the oven and bake for another 15-20 minutes–topping should be brown and bubbling here and there and the edge crust should be brown but not burned.
Cool pie on a wire rack for at least 2 hours in order for the filling to set up. Serve at room temperature, or cold. Store, covered, in the fridge for up to 5 days.