1. Process flour, salt, and sugar together in food processor until combined, about 3 seconds. Add butter and pulse until butter is size of large peas, about ten 1-second pulses.

2. Using fork, mix sour cream and 1/3 cup ice water in small bowl until combined. Add half of sour cream mixture to flour mixture; pulse for three 1-second pulses. Repeat with remaining sour cream mixture. Pinch dough with fingers; if dough is floury, dry, and does not hold together, add 1 to 2 tablespoons ice water and process until dough forms large clumps and no dry flour remains, three to five 1-second pulses.

3. Turn dough out onto work surface. Divide dough into 2 balls and flatten each into 4-inch disk; wrap each disk in plastic and refrigerate until firm but not hard, 1 to 2 hours, before rolling. (Dough can be refrigerated for up to 24 hours. Let thoroughly chilled dough stand at room temperature for 15 minutes before rolling.)

Makes one 9-inch double-crust pie shell