Prepare the Pie Crust: In a large bowl, whisk together the flour and salt. Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs. Gradually add the ice water, one tablespoon at a time, mixing until the dough just comes together. Be careful not to overmix. Divide the dough in half, flatten each half into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes. Chilling the dough is crucial for a flaky crust, so don't skip this step!

Make the Blueberry Filling: In a large bowl, combine the blueberries, granulated sugar, flour, lemon juice, lemon zest, and ground ginger. Gently stir until all the blueberries are coated. The lemon juice will help to macerate the blueberries, making them extra juicy.

Roll Out the Bottom Crust: On a lightly floured surface, roll out one disc of dough into a 12-inch circle. Carefully transfer the dough to a 9-inch pie plate. Trim the edges, leaving about a 1-inch overhang. Crimp the edges or use a fork to create a decorative border.

Add the Filling: Pour the blueberry filling into the prepared pie crust. Dot the top with small pieces of butter. This will add richness and flavor to the filling.

Roll Out the Top Crust: Roll out the remaining disc of dough into a 12-inch circle. Carefully place it over the filling. Trim the edges, leaving about a 1-inch overhang. Crimp the edges together with the bottom crust to seal. Cut a few slits in the top crust to allow steam to escape while baking.

Egg Wash and Sugar (Optional): Brush the top crust with the beaten egg for a golden-brown color. Sprinkle with turbinado sugar for a little extra sparkle and crunch, if desired.

Bake the Pie: Preheat your oven to 400°F (200°C). Place the pie on a baking sheet lined with parchment paper. Bake for 45-50 minutes, or until the crust is golden brown and the filling is bubbling. If the crust starts to brown too quickly, you can cover the edges with aluminum foil.

Cool the Pie: Remove the pie from the oven and let it cool completely on a wire rack before slicing and serving. This is the hardest part because the pie smells so good, but letting it cool allows the filling to set properly.