This jewel-box of a pie is from The America's Test Kitchen Family Baking Book.
FOR THE CRUST:
1. Adjust oven rack to middle position and heat oven to 325 degrees. In a food processor, process
9 graham crackers until evenly fine, about 30 seconds (you should have 1 cup crumbs). Add
2 Tablespoons granulated sugar and pulse to combine. Melt 5 Tablespoons unsalted butter and continue to pulse while adding warm melted butter in steady stream; pulse until mixture resembles wet sand.
2. Transfer crumbs to 9-inch glass pie plate, forming crust evenly in bottom and up sides. Bake crust until fragrant and beginning to brown, 15 to 18 minutes; transfer to wire rack and cool completely while making filling.
FOR THE FILLING:
1. Combine 2 cups fresh raspberries, 2 cups fresh blackberries, and 2 cups fresh blueberries in large colander and gently rinse (taking care not to bruise them); spread berries on paper towel-lined rimmed baking sheet and gently pat dry with additional paper towels.
2. In food processor, puree 2 1/2 cups of the mixed berries until smooth and fully pureed, about 1 minute. Strain puree through mesh strainer into small saucepan, scraping and pressing on seeds to extract as much puree as possible (you should have 1 1/4 to 1 1/2 cups). Whisk 1/2 cup granulated sugar,
3 Tablespoons cornstarch, and 1/8 teaspoon salt in small bowl to combine, then whisk mixture into puree. Bring puree to boil over medium heat, stirring constantly with wooden spoon; when mixture reaches a boil and is thickened to consistency of pudding, remove from heat, stir in 1 Tablespoon lemon juice, and set aside to cool slightly.
3. While puree is cooling, place remaining berries in medium bowl. Heat 2 Tablespoons red currant jelly* in second small saucepan over low heat until fully melted; drizzle melted jelly over berries and toss gently to coat. Pour slightly cooled puree into cooled pie shell; top with fresh berries. Loosely cover pie with plastic wrap; refrigerate until chilled and puree has set, about 3 hours (or up to 1 day).
FOR THE WHIPPED CREAM:
1. Just before serving, beat 1 cup cold heavy cream, 1 Tablespoon granulated sugar, and
1 teaspoon vanilla extract with electric mixer on low speed until small bubbles form, about 30 seconds. Increase speed to medium; continue beating until beaters leave trail, about 30 seconds longer. Increase speed to high; continue beating until cream is smooth, thick, nearly doubled in volume, and forms soft peaks, about 30 to 60 seconds.
2. Cut pie into wedges and serve with whipped cream.
*Apple jelly can be substituted for the red currant jelly.