- Combine flour, sugar and salt in food processor; pulse to blend.
- Add butter and shortening and cut into flour mixture using on/off turns. When mixture resembles coarse meal, transfer to large bowl.
- Combine 4 tablespoons ice water and cider vinegar in small bowl; pour over flour mixture. Stir with fork until moist clumps form, adding additional 2 tablespoons ice water if necessary.
- Gather dough into 2 balls and flatten balls into disks. Wrap in plastic and chill 30 minutes or up to 4 days. Well-wrapped dough can be frozen up to 2 weeks. Allow dough to soften slightly at room temperature before continuing.