Divide the butter cubes into two portions:

1. For a single crust: 5 tablespoons and 3 tablespoons (2.5 and 1.5oz)
2. For a double crust: 9 tablespoons and 5 tablespoons (4.5oz and 2.5oz)
3. Wrap each portion in plastic wrap. Put the larger portion in the refrigerator and the smaller portion in the freezer for at least 30 minutes.
4. Place the flour, salt, and baking powder in a gallon size ziplock bag and put in the freezer for at least 30 minutes.

Make the dough:

1. Place the flour mixture in the food processer and pulse a few times until well combined. Add the larger amount of butter cubes and process until the mixture resembles coarse meal, about 20 seconds.
2. Add the remaining frozen cubes of butter and pulse until they are the size of small peas.
3. Add the vinegar and lowest amount of ice water and pulse 6 times.
4. Test the mixture by pressing a small amount between your fingers. If it holds together, it doesn't need the extra water. If it doesn't hold together, add the remaining water and pulse 3 times.
5. The mixture will not come together in a mass in the processor. It will be in smaller pieces that come together when pressed.
6. Working quickly and gently, press the dough together and form into a disk for a single crust or 2 disks for a double crust pie. Wrap in plastic wrap and refrigerate for at least 45 minutes and preferably overnight.

Rolling the dough:

1. When you are ready to roll out the pie crust, remove the dough from the refrigerator. Allow it to soften on the counter for 10 minutes. Lay out 2 pieces of overlapping plastic wrap on the counter and lightly dust with flour.
2. Set dough disk in the middle of the plastic and cover with 2 more overlapping pieces of plastic wrap. Working quickly, roll out the dough evenly into a 13-inch circle for a 9-inch single-crust pie. Roll 2 12-inch circles for a double crust pie. The dough should be about 1/8 of an inch thick.
3. I find that I get the most circular shape when I roll outwards from the middle, rotating about 45 degrees after each roll. If I can't rotate the plastic wrap, I just rotate my direction of rolling, keeping the plastic wrap stable on the counter. For example, if the first roll is towards the north, the next roll is towards north-east. The next roll would be towards east, then south-east, then south, continuing around the circle.
4. Using a 13-inch cardboard circle as a guide for a single pie crust (12-inches for double-crust), carefully trim the dough into a circle.
5. Ease the dough into the pie dish, being careful not to stretch it. The overlap should be the same on all sides.
6. For a single-crust pie fold under the excess dough and make an even rim of dough. Flute or crimp the edge as desired.
7. Refrigerate the shell for at least an hour or stick it in the freezer for about 30 minutes.

Baking the crust:

1. Preheat the oven to 425 degrees F for 25 minutes before baking.
2. Line the pastry with parchment paper and fill with pie weights.
3. Bake on a baking sheet, on the bottom rack of the oven, for about 20 minutes until the edges are set.
4. Carefully lift out the parchment and the weights. Prick the bottom and sides with a fork to prevent bubbles. Bake for another 10 minutes until the crust is golden brown.

For a double crust pie:

1. After easing the crust into pie dish, trim the excess to 1/2- inch past the rim.
2. After filling the pie, brush this edge with a little water. Gently place the top crust over the filling and fold the edges under the excess of the bottom crust. Press into an even rim of dough and flute or crimp as desired.
3. Refrigerate the pie for an hour to help the fluted edge keep its shape during baking.
4. Cut slits for steam vents just before baking.