In the bowl of a food processor, pulse together flour, sugar, and salt. Add cold butter cubes and pulse until the mixture resembles a coarse meal.
Add water in small increments, pulsing between additions, until the dough is evenly moist and hold together when pressed between fingers.
Remove blade and turn dough out onto a well floured surface. Work into a cohesive mass, then divided in half. If your kitchen is warm or humid, work the dough balls into small disks, wrap in plastic and refrigerate for 30 minutes before rolling. If your kitchen is cool, roll out dough to fit your pie plate with an overhang of approximately one inch.
Prepare pie dish by buttering and dusting with flour, shaking out excess. Place dough round in pie dish and fill with cooled pie filling.
Roll out top round and place onto of filling. Trim any excessive over hang to approximately one inch and pinch bottom and top crusts together. Tuck edges under. Crimp edges using preferred method. Cut a small venting slit and dock the top crust 4-6 times to help release steam during cooking. Brush with egg wash and sprinkle with sugar if desired.
Place pie dish on a baking sheet and cook in a 375 degree oven for 20 minutes. Reduce heat to 325 and continue cooking for 20-25 minutes or until the crust is golden brown.
Remove from oven and cool before serving