On a lightly floured surface, roll one portion of All-Butter Pie Dough into a 17x13-inch rectangle. Transfer to a 14½x9½-inch rimmed baking sheet, pressing into bottom and up sides of pan. Cover with plastic wrap, and refrigerate.

Line 2 baking sheets with parchment paper.

On a lightly floured surface, roll each remaining portion of pie dough into a 16x12-inch rectangle. Using a sharp knife, cut each portion of dough into 16x1-inch strips. Place strips on prepared pans. Cover with plastic wrap, and refrigerate.

In a large heavy-bottomed saucepan, bring 2 pounds (907 grams) blueberries, granulated sugar, cornstarch, lemon zest and juice, salt, and cinnamon to a boil over medium heat, stirring frequently, until thickened, 10 to 15 minutes. Remove from heat, and let cool completely. Stir in remaining ½ pound (226 grams) blueberries and vanilla.

Spread blueberry mixture into prepared crust; dot with butter cubes. Arrange dough strips crosswise on filling or in a lattice pattern if desired. Trim edges of dough strips; fold edges under, and crimp as desired. Using a pastry brush, brush egg onto dough strips. Sprinkle with turbinado sugar. Freeze for 20 to 25 minutes.

Position oven rack in bottom third of oven. Preheat oven to 425°F (220°C).

Line a very large baking sheet with foil; place pie on prepared pan.

Bake for 20 minutes. Reduce oven temperature to 350°F (180°C), and bake until crust is golden brown and filling is bubbling, 40 to 50 minutes more. (Loosely cover pie with foil after 30 minutes to prevent overbrowning, if necessary.) Let cool completely on a wire rack before serving. Serve with Mascarpone Whipped Cream. Store, covered, at room temperature for up to 2 days.