In a large mixing bowl, whisk together the sugar, cornstarch and cinnamon. Add the grated apple, lemon juice and zest. Toss with a spatula to combine. Add the blueberries and gently toss in the sugar mixture until combined. Set aside until the blueberries start to release their juice, 20 to 30 minutes.

While the blueberries macerate, roll out half of the prepared pie dough. Roll the pastry into a circle large enough to fit in a deep dish pie plate with a 1-inch overhang. Gently ease the pastry into the pie plate taking care not to stretch the dough while pressing into the corners. Place the pie plate and pastry in the refrigerator to chill until ready to fill with blueberries.

Pour the blueberries and any juices into the prepared pie crust. Dot with small pieces of butter. Return the pie plate to the refrigerator to keep cool while rolling out the top crust.

Roll the top crust into a circle about 2-inches larger than the top of the pie plate. Cut into strips for a lattice crust design and create a weave over the fruit. Wet your finger with ice water and spread it on the crust pieces that are being folded together. Trim the excess dough and fold the over-hang up and over the lattice pieces. Pinch together to seal and crimp into a decorative edge, as desired.

Brush the pie crust lightly with 1 egg beaten with 1 teaspoon of milk. Sprinkle with coarse sugar and place on the foil baking sheet in the oven.