In a medium saucepan, combine cherries, granulated sugar, ½ cup water, cornstarch, lemon juice, and vanilla bean seeds over medium-high heat. Stir gently to combine. Bring to a boil, and reduce heat to low. Cook until thickened, stirring frequently, being careful not to crush cherries, about 10 minutes. Remove from heat, and let cool.
Preheat oven to 375°F.
On a lightly floured surface, roll half of dough into a 12-inch circle. Transfer to a 9-inch pie plate, pressing into bottom and up sides. Trim dough to ½ -inch beyond edge of plate. Spoon cherry filling into dough.
On a lightly floured surface, roll remaining dough into a 12-inch circle. Cut dough into strips of varying widths. Place dough strips on pie in a lattice design. Trim dough strips, fold edges under, and crimp as desired. Brush dough with beaten egg, and sprinkle with turbinado sugar. Place pie on a baking sheet.
Bake until golden brown and bubbly, 40 to 50 minutes. Let cool for at least 2 hours before slicing.
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/washington-cherry-pie/