Wash and peel the peaches and pit the seeds. Slice the peaches into even-sized pieces and add to a bowl.
Add cornstarch, sugar, brown sugar, cinnamon, lemon juice, and cubed butter to the peaches and mix until well combined.
Assemble Peach Pie-
Preheat the oven to 375°F.
With a rolling pin, roll out one of the disks into a 12" round circle. Transfer to a 9" pie dish and pat down, allowing the extra dough to hang over the dish. Roll out the second pie dish into 9" round circle.
Add the pie filling along with all the juices into the pie dish and top with the second pie crust and crimp the edges to seal.
Brush the topping with egg wash and top with coarse sugar.
Cover the pie with foil and bake the pie at 375°F for about 45 minutes.
Remove the foil from the pie and bake for an additional 15 minutes, or until the pie crust is golden and crispy.
Remove the peach pie from the oven and allow to cool for atleast 20 minutes before serving.