Southern sweet potato and pecan pie

It is mid-March here in Johannesburg, and Fall is rapidly creeping in. Mornings are getting cooler, leaves are starting to fall, and I am now craving food I would normally expect to find around October or November in the Northern Hemisphere. Hence this typical Southern dessert that classically adorns every table at Thanksgiving. It's all about the contrast of textures: soft creamy sweet potato, crispy crust and crunchy pecan topping. Ingredients Pie Crust 1 1/4 cup all purpose flour 1 tsp granulated sugar 1/2 tsp salt 1/2 cup very cold unsalted butter cut in cubes 1/4-1/3 cup very cold water 1 egg (for egg wash) Sweet Potato Pie Filling 1 cup sweet potato mashed 1/4 cup salted butter melted and cooled 1 1/4 cup granulated sugar 2 large eggs beaten 2 tsp vanilla extract tsp ground cinnamon 1/8 tsp ground nutmeg Pecan Pie Topping 1 large egg room temperature and beaten 1 1/4 cup chopped pecans 1/4 cup granulated sugar 2 tbsp light brown sugar...