Martha and Emmy-winner Jean Smart bake a mixed-berry slab pie.
Preheat oven to 375 degrees. On a lightly floured surface, roll out larger piece of dough to an 18-by-13-inch rectangle. Fit into a 15-by-10-inch rimmed baking sheet, pressing into corners (pastry will hang over sides). Chill while assembling filling.
In a large bowl, stir together berries, granulated sugar, cornstarch, lemon juice, and salt. Spread mixture over chilled pie shell.
On a lightly floured surface, roll out remaining piece of dough to a 16-by-11-inch rectangle; drape over filling. Fold edge of bottom dough over top dough. Pinch edges to seal. Prick top dough all over with a fork. Brush entire surface of pie with cream, and sprinkle with sanding sugar.
Bake until crust is golden brown and filling is bubbling, 40 to 55 minutes. Transfer to a wire rack, and let pie cool until it is just warm to the touch, about 45 minutes. Serve warm or at room temperature, cut into 12 pieces. Slab pie is best eaten the same day it is baked, but it can be kept at room temperature, loosely covered with plastic wrap, for up to 2 days.