Prepare the pie crust dough. The dough should be separated into two discs (one for the top crust and one for the bottom crust) and will need to be refrigerated for at least 2 hours before using.

In a large pot, combine blueberries, both sugars, cornstarch, orange juice, cinnamon, and salt. Stir gently to coat the blueberries.

Cook the filling on the stove on medium-low heat until the berries release their juices, about 10 minutes. Stir the mixture frequently while cooking.

Turn the heat up to medium and continue to cook, stirring frequently, until the filling thickens and begins to bubble, about 10 more minutes. Let the filling cook while bubbling for 1 minute.

Transfer the filling to a heat-safe bowl and let it cool to room temperature.

Ten to fifteen minutes before you plan to begin assembling the pie, remove the pie crust dough from the fridge and place on a cooling rack to soften slightly.

Lightly sprinkle flour onto a clean counter or surface for rolling out the dough and onto your rolling pin. Place one unwrapped disc of dough onto the floured surface and roll the dough into a circle that's 12 inches in diameter. Carefully transfer the rolled out crust to your pie plate.

Pour the room temperature pie filling into the pie crust in the pie plate.

Lightly sprinkle more flour onto the counter and rolling pin, then roll out the other disc of dough into a circle that's 12 inches in diameter.

Place the rolled out dough over the filling in the pie plate (or create a lattice pie top). Trim any excess pie crust from the edges, then seal or crimp the edge.

Prepare an egg wash by whisking together an egg with 1 Tablespoon of water until well blended. Brush the egg wash over the crust. Sprinkle turbinado sugar over the egg wash.

Bake the pie at 425°F for 20 minutes. Then turn the oven temperature down to 350°F and continue baking for 45-50 minutes until the crust is golden and the filling is bubbling.

Allow the pie to cool completely (ideally overnight) on a wire rack before serving to ensure that the filling has time to set.