Rhubarb Raspberry Pie - Frozen-butter pastry dough

Method

• Divide dough into 2 pieces (1 piece should be slightly smaller than the other).
• Chill larger dough piece, wrapped in plastic wrap.
• On a lightly floured surface with a lightly floured rolling pin roll out smaller piece of dough into a 10-inch round (about 1/8 inch thick).
• Transfer round to a large baking sheet and chill, covered.
• Roll out remaining dough into an 11-inch round (about 1/8 inch thick) and stack it on top of first round.
• Chill pastry rounds, loosely covered with plastic wrap, at least 1 hour, or until firm.
• Cut enough rhubarb crosswise into 1/2-inch slices to measure 4 cups.
• In a 3-quart kettle stir together 3 cups rhubarb, 1 cup sugar, and cinnamon and cook over moderate heat, stirring constantly, until sugar is melted, about 6 minutes.
• In a small bowl stir together cornstarch and lemon juice.
• Add cornstarch mixture to rhubarb mixture and boil, stirring constantly, until rhubarb is thickened, about 5 minutes, and transfer mixture to a bowl.
• Cool mixture to room temperature, about 30 minutes.
• Fold raspberries and remaining cup rhubarb into mixture until just combined.
• Chill rhubarb filling, covered, at least 30 minutes, or until cold.
• Preheat oven to 425F.
• In a small bowl whisk together egg and milk to make an egg wash.
• Fit 11-inch round of dough into a 9-inch (1-quart) glass pie plate and trim with scissors, leaving a 1/2-inch overhang.
• Spoon rhubarb filling into shell, smoothing top, and brush edge of crust with egg wash. Drape remaining pastry round over filling and trim, leaving a 1/2-inch overhang.
• Crimp edge decoratively.
• With a sharp small knife score a decorative pattern on crust and brush crust evenly with some egg wash. Sprinkle crust with remaining 2 tablespoons sugar.
• Bake pie on a baking sheet in middle of oven 35 minutes, or until crust is golden brown and cooked through.
• (If pastry gets too brown too quickly, tent pie with foil.)
• Transfer pie to a rack.
• Cool pie at least 1 hour to set filling.
• Serve pie with ice cream.