1. Measure cold milk or water into a liquid measuring cup with pour spout. Add vinegar and place in freezer to chill while you prepare your work area and gather your ingredients in one place. It is important to work quickly.
2. Fluff the flour inside your cannister and scoop it into the measuring cup; level the top with a knife and place in bowl. Sprinkle salt and sugar over; whisk thoroughly.  
3. Cut perfectly cold butter in ¼-inch slices and add to flour mixture. Toss them in a few at time and coat all sides of the butter pieces with flour. Now pick up the pastry blender and, working quickly, chop the butter into the flour with quick, even strokes. As the tines clog with butter, use your fingers (carefully, it’s sharp) or a butter knife to release the butter. Continue cutting it in until the pieces range from flakes to small peas. 
4. Retrieve the vinegar mixture from the freezer and drizzle it over the mixture. Use the dough card to fold the mixture over on itself a few times until the water disappears. Next, use your dominant hand to scoop up the flour mixture, fold it back over itself, and press down firmly. Rotate the bowl a quarter turn with your other hand and repeat lifting, folding, pressing, the mixture over itself until it begins to form a mass. Do your best to incorporate any bits of flour or dough that are sticking to the bowl and stop working it as soon as it forms dough.
5. Sprinkle about 2 tablespoons of flour on the counter and set the dough in the center. Quickly pat the dough into a rough mound and cut it in half. Pat each half into a disc about 1-inch (2.5 cm) thick. Use your hands to pat the edges of each disc as smooth as you can. Place the dough discs side-by-side in a square baking pan or on a plate and slip it inside a plastic bag, securing it closed. Refrigerate at least 2 hours or overnight.

The next day (or 2 hours later): 

1. Remove one disc of Butter Pie Crust from the fridge and let it sit at room temperature for 10-15 minutes while you prepare your work area and ingredients.
2. Sprinkle a few drops of water on a clean work surface (or mist lightly with a spray bottle of clean water) and place a piece of parchment paper on top to hold it in place. Sprinkle parchment paper with flour. Place Butter Pie Crust dough in the center and sprinkle with flour. Use a rolling pin to roll the dough from the center outward to form a circle. Rotate by quarter turns to ensure an even, round shape and sprinkle with a little more flour if needed once the pastry is about half rolled out. Roll to an even 12-13-inch pie crust.
3. Before you are done rolling the first crust out, bring the second pastry disc out of the fridge to sit at room temp for 10 minutes and place a rack in the middle of the oven with another rack below. Line a cookie sheet with aluminum foil and have ready. Preheat the oven to 425°F (220°C)
4. Lift one side of parchment paper and fold the pastry over on itself in half. Peel the paper back by half and settle the exposed half of pastry in the pie pan. Peel the parchment paper off the remaining half; unfold the pastry. Settle it gently into the pan without stretching so that it covers the entire bottom and sides of the pie pan. Use a paring knife to trim the overhang, reserve the scraps for any needed repairs and for decorations, if you wish.
5. Add your fruit pie filling of choice to your unbaked pie shell. Roll the second disk of dough out as the first and place on top of the filled pie dish. Fold overhang under the lower crust and press to seal. Crimp as desired, cut vents in the top and bake as your pie recipe directs.

Note: If you are making a single crust pie, leave a generous edge on the pie crust. Fold it under itself around the edge and crimp as you like. Single crust pies are generally baked before the filling is added.