Preheat the oven to 425 degrees F. Line a 3/4 sheet pan with pieces of parchment paper. Set aside.
Roll out pie crust in a rectangle shape, slightly larger than the half sheet pan.
Line a half sheet pan with parchment paper and lightly spray with cooking spray.
Place the blueberries in a large bowl. Add the sugar, lemon juice, and instant tapioca. Combine with a large spoon. Set aside.
Fold the pie crust bottom up gently and place on the half sheet pan carefully. Unfold and press into the pan gently. Cut away any excess pie dough with kitchen shears. (You want about 1 inch over the pan.)
Pour the blueberry mixture on the bottom pie crust. Sprinkle with cinnamon and nutmeg evenly.
Roll out another piece of pie crust in a rectangular shape. Cut strips of pie crust with a pastry cutter or small pizza cutter.
Lay strips of pie crust going one way. Pull back every other piece and lay pie crust strips going the opposite way. Work your way from one section of the pie to the other end continuing the lattice weaving process.
Brush the entire pie with an egg wash and sprinkle with a generous helping of granulated sugar. Place the pie on the larger sheet pan to help catch any juices and make clean up easier.
Bake for 1 hour at 425 degrees F. Then turn the oven down to 400 degrees F and continue baking until the pie crust is evenly browned and the filling bubbling up around the edges.
Remove the pie from the oven and set on a baking rack to cool for 1 1/2 hours in order for the pie filling to set properly.