For a great, flakey, butter crust, make sure not to knead it too much. Just enough that it comes together in a rough ball. Also try be efficient when working with your hands in the dough. You want to keep the butter cold-cool, and your hands will warm it up quickly. This dough amount makes enough for two 9-inch pie doughs. Either for two bases or for one base and one top. If you are using the top for decorative crusts, excess dough can also be kneaded together again and rolled out for decorative cuts. The dough will need to rest for about 15 minutes after kneading to relax and it will not be as tender, but if it just for decorative pieces, that usually isn't noticeable.
1cup(227g)cold unsalted butter, (2 sticks) cut into 1/2-inch (12mm) pieces
1/2cup(120ml)cold water (you may not end up using the full amount)
egg wash(1 egg beat with @ 2 tablespoons water), (or heavy cream) for brushing crust
In a bowl, combine the flour, sugar, and salt. Add the butter and pinch with your fingers or use a to cut the butter into the flour until it resembles coarse crumbs or until most of the big chunks of butter are flattened or broken up and there is no remaining dry flour sections.
Mix in enough of the cold water into the the dough until it comes together and forms a rough ball. If necessary, barely knead the dough just until the can come together nicely in a ball, dusting the surface with flour as you work to keep things from sticking. Don't overwork the dough or else it will become tough.
Divide the dough ball in half and then roll each half into a ball, and then flatten into a disk. Wrap in plastic wrap and chill for at least 30 minutes (can be chilled overnight or frozen for future use).Use as directed in your pie recipes. Make sure to butter the base of your pie pans before adding the dough and brush with egg wash or heavy cream before baking.