Cut in the butter with a pastry cutter or with your fingertips, working quickly until pieces are the size of small peas.
Gradually sprinkle the cold water over the mixture, mixing lightly with a fork after each addition. Add only enough water to hold the pastry together.
Gently shape the pastry into a disk, wrap in plastic wrap, and allow it to rest in the refrigerator for at least 30 minutes before rolling out and placing in your pie pan.
Chill thoroughly in the pie pan before assembling your pie.
Notes
Makes enough for two 9-inch 1-crust pies or one double crust pie.