Special equipment: 9-inch aluminum pie pan
Make the Crust: In a food processor combine the flour, sugar, and salt. Add the butter and pulse until pea-sized pieces appear.
In a small bowl, stir the water and vinegar together.
Add the vinegar mixture and pulse briefly¿it will still look crumbly. Transfer the crumbs to a work surface and shape into a round, flat disk. Wrap in plastic wrap and refrigerate at least 30 minutes before using. (Or, refrigerate up to 48 hours or freeze up to 1 month before using. If frozen, let thaw in the refrigerator overnight before rolling out.)
When the time comes to roll out the dough, let the dough warm up for a few minutes at room temperature to make it more workable. Dust a work surface with just a few tablespoons of flour and keep some extra flour at hand. Sprinkle a little flour on top of the dough and start rolling outward from the center with quick, light strokes. Don't worry if the edges split a bit; concentrate on forming a good circle from the center. Lift up and rotate the dough 1/4 turn every minute or so to help ensure even rolling. The dough should feel smooth and soft; some say it should feel like the inside of your forearm. If it gets sticky, sprinkle on a bit more flour, but don't do this more than 2 or 3 times; the dough will absorb too much flour. Instead, put it back in the refrigerator for 15 minutes to firm up the butter. Keep rolling until the circle is at least 2 inches larger than your pan (for example, 11 inches wide for a 9-inch pie pan), or 3 inches larger for deep-dish pies.
Set your pie pan nearby. We always use heavy aluminum pans, because glass pans seem to bake the crust too fast. However, we know that the advantage of glass is that you can easily check the color of the crust. To transfer the crust to the pan, I find it easiest to roll a finished crust up onto the rolling pin, then gently unroll it in the pan. Or, you can fold it gently in quarters, lift it up, position the center point on the center of the pan, and unfold it into the pan. Make sure that the dough is allowed to settle completely into the pan.
Don't stretch and press the dough into the corners; stretched dough will likely shrink back when you bake it. Instead, lift the edges of the crust to let it settle down into the corners. If the dough tears a bit, don't be concerned; we'll patch it in a minute. Using scissors or a sharp knife, trim the dough to within 3/4-inch of the rim. Use any extra scraps to patch the crust, pressing with your fingers (wet them if necessary) or set aside. To decorate the rim, fold under the excess dough then just press it all around with the back of a fork. For a slightly more advanced look, press the thumb and forefinger of 1 hand together. Use them to gently push the thick dough rim outward, while pushing inward with the forefinger of the other hand, so that they intersect in a "V" with the dough in between. Repeat all around the rim to make a wavy edge. Chill 1 hour.
Preheat the oven to 425 degrees F. Line the shell with a sheet of foil and fill with raw rice or dried beans. Bake for 20 to 25 minutes. Remove the foil and rice and continue baking until golden brown. Let the pie shell cool on a rack while you make the filling.
Make the Filling: In a mixing bowl with a whip attachment, whisk together the yolks and 1/3 cup sugar until fluffy, then add the lemon juice and zest. Place the bowl over a saucepan of simmering water, and cook, whisking, until thickened, about 7 to 8 minutes.
Meanwhile, sprinkle the gelatin over cold water and let dissolve.
Remove the yolk mixture from the heat and whisk in the gelatin until dissolved. Place the mixture over an ice bath and stir with a rubber spatula to cool it. Once it's room temperature remove it from the ice bath and let it sit while you whip the meringue.
Place the egg whites in a clean dry bowl and whip on medium speed until foamy; then turn up to high and continue whipping until soft peaks form. Gradually add the remaining 1/3 cup sugar and whip until glossy and sugar has dissolved. Fold 1/3 of the whites into the lemon mixture; then fold in the remaining whites in 3 batches. Pour the mixture into the cooled pie shell and smooth the top.
Chill the pie at least 2 hours before serving. Serve with dollops of whipped cream.