Plum Blackberry Streusel Pie

Ingredients

• 1� pound ripe plums pitted and quartered
• 2 cups blackberries (this recipe used black raspberries.)
• 1� cups sugar, divided
• 3 Tablespoons quick-cooking tapioca
• 2 Tablespoons cornstarch
• 1 teaspoon grated lemon zest
• � teaspoon salt, divided
• � recipe Perfect Pie Dough (see below)
• 1 cup old-fashioned rolled oats
• � cup all-purpose flour
• 1 stick cold unsalted butter, cut into bits

Perfect Pie Dough

• 2 1/2 cups all-purpose flour
• 1 teaspoon salt
• 1 teaspoon sugar
• 1 cup (2 sticks) unsalted butter, chilled and cut into small pieces
• � cup ice water

Directions

1. Preheat oven to 375�F. (Use an �oven liner� to keep any drips from the filling from messing up your oven.)
2. Toss plums and blackberries with 1 cup sugar, tapioca, cornstarch, zest, and � teaspoon salt in a large bowl.
3. (see recipe instructions below for pie crust)
4. Roll out doughinto a 13-inch round on a lightly floured surface with a lightly floured rolling pin. Fit into a 9� inch deep-dish pie plate. Trim excess dough, leaving a � inch overhang. Fold overhang under and press against rim of pie plate, then crimp decoratively. Chill while making streusel.
5. Stir together oats, flour, and remaining � cup sugar and � teaspoon salt. Blend in butter with your fingertips until mixture forms small clumps.
6. Mound filling in shell. Crumble streusel evenly over filling.
7. Bake pie until streusel is golden and filling is bubbling, 1� to 1� hours. Cool completely, about 3 hours.

Perfect Pie Dough

1. In the bowl of a food processor, combine flour, salt, and sugar. Add butter, and process until the mixture resembles coarse meal, 8 to 10 seconds. With machine running, add ice water in a slow, steady stream through feed tube. Pulse until dough holds together without being wet or sticky; be careful not to process more than 30 seconds. To test, squeeze a small amount together: If it is crumbly, add more ice water, 1 tablespoon at a time.
2. Divide dough into two equal balls. Flatten each ball into a disc and wrap in plastic. (Pressing the dough into a disc rather than shaping it into a ball allows it to chill faster. This will also make the dough easier to roll out, and if you freeze it, it will thaw more quickly.) Transfer to the refrigerator and chill at least 1 hour. Dough may be stored, frozen, up to 1 month.
3. By following these seven simple rules, you can produce a flaky, tender crust every time:
4. 1. When making the dough, make sure the butter is very cold.
5. 2. Handle the dough as little as possible. Both the stretching of the dough and the warmth from your hands will further the development of gluten -- long, stringy protein molecules that form when flour is blended with liquid -- resulting in a tough dough that's difficult to roll out.
6. 3. Since our pie-dough recipe yields two single crusts, divide the dough in half, and pat each half into a flat disk before wrapping it in plastic and chilling. This will make it easier to roll out each crust into a perfect circle.
7. 4. Chill the dough thoroughly (at least 30 minutes) before rolling it out, and use a minimum of flour to dust the rolling pin and work surface. Brush excess flour from the rolled dough with a dry pastry brush before transferring it to the pie plate.
8. 5. For an extra-crispy piecrust with a golden color, brush the unbaked top crust with water, and sprinkle it with sugar.
9. 6. For a shiny piecrust, brush the unbaked top crust with an egg wash made from one egg and 2 tablespoons cream.
10. 7. Cut decorative vents in the top of a double-crusted fruit pie; vents allow steam to escape and prevent the fruit juices from overflowing.