Difficulty: Moderate
Preparation time: 90 minutes
 

• 1. In a large bowl, toss the cubed butter and flour together. Using your fingers, smear the butter and flour together to form thin flakes. Continue until the mixture starts to come together in a shaggy mass. Add just enough cold water to bring the dough together. Wrap with plastic and refrigerate for 30 minutes.
• 2. While the dough is resting, make the filling. Place the cornstarch and water in a large bowl and whisk to combine. Stir the jam into this mixture. Add the frozen fruit and mix thoroughly. Set aside.
• 3. Preheat oven to 350°F. Divide the dough in half. Lightly flour your work surface and roll out the dough into two 13-inch circles, about ⅛-inch thick. Transfer one of the dough circles to a 9-inch pie tin. Add the filling. Top with the second dough round, making sure you cut several openings in the top to allow steam to vent. You can cut long slits, punch out a series of small holes, or make a lattice top if you prefer. Trim any excess dough, then fold the edges of the top and bottom dough together to form a crust. Brush the crust with the egg, then sprinkle with coarse sugar.
• 4. Place the pie tin on a parchment-lined baking sheet to catch any overflow. Drape a piece of aluminum foil over the top crust to prevent overbrowning. Bake pie for 25 minutes then rotate and remove the foil. Bake for an additional 45 minutes, or until the crust is a deep golden brown and the filling is bubbling. Allow to cool completely before serving.