Two 9-inch pie crusts, or two 9 1/2 or 10-inch tart crusts or one 9-inch covered pie crust.
This dough is richer in fat than ordinary flaky pastry and is thus softer and more difficult to handle, but it yields a marvelously tender, flaky crust with a superb butter flavor. While it is possible to make this dough with butter only, a small amount of shortening makes it flakier without interfering with the buttery taste.
Since this dough tends to puff out of shape during baking, you should not use it to make a crust with a tightly fluted or braided edge. If you need only a single pie or tart crust, decrease all ingredients by half or freeze half the dough for another pie.
Using a rubber spatula, thoroughly mix in a large bowl:purpose flour, white sugar, powdered sugar, salt
Working quickly to prevent softening, cut into 1/4-inch pieces:cold unsalted butter
Add the butter to the dry ingredients. Using a pastry blender or two knives, chop the butter into pea-sized pieces. Add:solid vegetable shortening
With a few quick swipes of the pastry blender, cut the shortening into large chunks and distribute throughout the bowl. Continue to chop with the pastry blender until the mixture resembles coarse crumbs with some pea-sized pieces. Do not let the mixture soften and begin to clump; it must remain dry and powdery. Drizzle over the flour and fat mixture: ice water
Cut with the blade side of the rubber spatula until the mixture looks evenly moistened and begins to form small balls. Press down on the dough with the flat side of the spatula. If the balls of dough stick together, you have added enough water; if they do not, drizzle over the top:ice water
Cut in the water, then press with your hands until the dough coheres. The dough should look rough, not smooth. Divide the dough in half, press each half into a round flat disk, and wrap tightly in plastic. Refrigerate for at least 30 minutes, preferably for several hours, or for up to 2 days before rolling. The dough can be wrapped airtight and frozen for up to 6 months; thaw completely before rolling.