Stir together the flours and sugar in a medium bowl. Use a pastry blender to cut in the butter until the mixture is crumbly. Sprinkle with 1 tablespoon of the ice water and stir with a fork until the mixture clumps together to form a dough. Add the remaining tablespoon ice water, if necessary.
Press the dough over the bottom and up the sides of a 9-inch (23 cm)