In a small bowl, mix together 4 tbsp of ice water and the apple cider vinegar and set aside.Place the flour, sugar and salt in the bowl of a food processor and pulse to combine. Add the cubes of butter and pulse until it resembles a coarse meal. With the motor running, drizzle in the vinegar and water mixture and process until moist clumps form. Pick up a handful of dough and squeeze it in your hand. If it holds together, you're done. If it seems crumbly, add more ice water, only *one teaspoon* at a time, and pulse to incorporate.

Turn the dough onto a lightly floured counter top and gather it until it just holds together. Shape it into a ball, and then press into a disk 1 1/2 inches thick. It's okay if it cracks a bit at the edges, just smooth the cracks with your fingertips. Wrap the disk snug in plastic wrap and press it a little more. Smooth away the cracks around the edges. Put the disk in the refrigerator for at least two hours. Remove from the fridge about 10 minutes before you're ready to roll the dough out to allow it to soften slightly.

With a lightly floured rolling pin, roll the disk out into a 12" circle large enough to fit a 9" pie dish. Transfer it to the pie dish, and gently press it into the dish. Trim the edge, leaving a 1/2" overhang. Fold the overhang under and lightly press against the rim of the pie dish, and crimp with a fork. Place the pie crust in the freezer for up to 10 minutes, or in the fridge for at least 30 minutes while you prepare your filling.