Preparation

• 面团塑造成一个1-inch-thick磁盘,包装plastic, and refrigerate to firm a bit, 20 to 30 min. You want the dough to remain pliable enough to roll, but not so soft that it’s sticky and difficult to move once it’s rolled out. Lightly flour a clean surface and your rolling pin. Roll out the dough into a 1/8-inch-thick round. (Run a dough scraper under the dough after every few passes of the rolling pin to prevent sticking, and reflour the surface as necessary.) Lay the rolling pin in the center of the crust, fold the pastry over it, and transfer it to a 9-inch pie pan. Gently press the dough into the pan. Trim the overhang to about 1/2 inch. (You’ll have about 6 ounces of excess dough.) Fold the overhang under to build up the edge of the pastry; crimp to flute the edges. Prick the entire surface, including the sides, with a fork. Cover loosely and refrigerate for half an hour. Meanwhile, heat the oven to 400°F.
• Apply a light coating of nonstick cooking spray to one side of a piece of aluminum foil that’s slightly larger than the diameter of the pie pan. Line the pan with the foil, oiled side down, going up and over the edges, and fill with pie weights, raw rice, or dried beans. Set the pie pan on a baking sheet and bake for 20 min. Carefully remove the foil and pie weights and bake until the crust is golden brown, about another 15 min. Transfer the pie crust to a rack and let cool while you make the filling.
• Gently rinse the berries and spread them on a paper-towellined baking sheet to dry (keep the berries separate). Hull the strawberries and slice them 1/4 inch thick. Combine the 1 cup blueberries, sugar, cornstarch, 1/4 teaspoon kosher salt, and 2/3 cup water in a medium-size saucepan. Set the pan over medium heat and bring to a boil, stirring frequently. Cook, stirring constantly, until the mixture turns deep purple, thickens, and becomes translucent instead of cloudy looking, 1 to 2 min. once the mixture begins bubbling. Remove from the heat and stir in the 1 cup strawberries, butter, and lemon juice. Sprinkle the 1 cup raspberries over the bottom of the pie crust and pour the filling over the top. Refrigerate until firm, about 4 hours.
• Just before serving, whip the cream to medium-firm peaks with the confectioners’ sugar and the vanilla extract and mound on top of the filling. Scatter the remaining berries over the whipped cream for garnish. Serve immediately.

Make Ahead Tips

You can bake and fill the pie crust with the berry mixture up to 12 hours in advance. When you’re ready to serve, whip the cream and garnish the pie.