For the press-in crust:
1 1/2 cups all-purpose flour, plus more as needed
1 teaspoon granulated sugar
1/4 teaspoon fine salt
8 tablespoons cold, unsalted butter (1 stick), cut into small pieces, plus more for coating the pan
4 to 5 tablespoons ice water
For the filling:
2 pounds ripe peaches, pitted and cut into sixths (about 6 cups)
1/2 cup granulated sugar
1/4 cup packed dark brown sugar
1 vanilla bean, split lengthwise and scraped, seeds reserved (or 1 tablespoon vanilla extract)
1 teaspoon freshly squeezed lemon juice
2 pints raspberries (about 12 ounces)
2 tablespoons cornstarch
For the streusel:
1/2 cup old-fashioned oats
1/4 cup all-purpose flour
1/4 cup packed dark brown sugar
1/8 teaspoon fine salt
4 tablespoons cold, unsalted butter (1/2 stick), cut into small pieces
INSTRUCTIONS
For the press-in crust:
- Coat a 9-1/2-inch deep-dish pie plate with butter and set aside.
- Combine the measured flour, sugar, and salt in the bowl of a food processor fitted with a blade attachment and pulse 5 times to evenly incorporate. Add the butter and pulse until just incorporated (some large pieces will remain). Drizzle in 4 tablespoons of the ice water and pulse until moistened throughout, about 5 pulses. (Add the last tablespoon of ice water if necessary, but do not overwork the dough or it will become tough.)
- Turn into the prepared pie plate. Press with floured fingers or the back of a measuring cup dipped in flour until the dough evenly covers the bottom and sides of the pie plate. Place in the refrigerator to chill, at least 20 minutes.
- Meanwhile, heat the oven to 400°F, arrange a rack in the lower third, and place a baking sheet lined with aluminum foil on the rack. When the oven is hot, pierce the base of the crust with a fork several times, line it with a piece of parchment paper, and fill it with pie weights or dried beans.
- Place the crust on the hot baking sheet and bake until dry to the touch but not browned, about 20 to 25 minutes. Remove from the oven, set aside the pie weights and parchment paper, and let the crust cool slightly on a wire rack. Return the baking sheet to the oven.
For the filling:
- Combine the peaches, sugars, vanilla seeds or extract, and lemon juice in a large, nonreactive bowl and gently mix. Add the raspberries and cornstarch and toss to coat. Transfer the filling to the crust and place the pie on the hot baking sheet. Bake until the peaches are just beginning to brown, about 30 minutes.
For the streusel:
- Meanwhile, combine all of the streusel ingredients except the butter in a medium bowl and mix until evenly incorporated. Add the butter and combine with your fingers, rubbing the butter into the flour mixture until mostly incorporated but some small pieces remain. Place in the refrigerator until ready to use.
- When the pie is ready, remove it from the oven and reduce the temperature to 375°F. Sprinkle the streusel over top and return the pie to the oven. Bake until the filling is bubbly, the streusel is browned, and the peaches are fork-tender, about 40 to 45 minutes more. Let cool on a wire rack at least 45 minutes before slicing.