In a large mixing bowl, mix flour and butter until coarse crumbs are formed. I used my hands for this process but you can use a pastry cutter.
Add sugar, salt, mix into coarse crumb mixture. Don't over mix as you'd want butter pieces/crumbs so crust will be baked flaky.
Add cold water and mix to form dough.
Split dough into two round, slightly flattened disks and freeze them while making pie filling.