For the crust, combine the flour, cinnamon, and salt. Cut in the butter with a pastry cutter, or use your fingers to break up the butter until a crumbly mixture results. Add water 1 Tbsp at a time until the dough just comes together. Gather the dough into a ball, wrap or cover, and chill for at least 45 minutes.
Remove the dough from the fridge and let it sit for 5-10 min to thaw. Divide the dough in half. On a lightly floured surface, roughly pat the dough into a ball and then a disk. Roll it out to about 12 inches in diameter. Gently transfer to the pie pan and refrigerate. Take the other half of the dough and roll it out again to 12 inches and cut 1-inch strips, these will be used as lattice. Cover and chill on a baking sheet until ready for bake.
In a large bowl, combine the filling ingredients (bourbon, sugar, cinnamon, salt). Then toss in the peaches.
Remove the pie crusts from the fridge. Add the peach filling (no liquid) to the prepared pie crust.
Preheat the oven to 350ºF.
To create the lattice, start with the interior strips (longest ones) and criss cross them in the middle of the pie. Then work your way out towards the shortest strips in an under-over pattern of your choosing, making sure you divide the strips evenly between left-right or top-bottom. Press the ends of the lattice strips onto the base pie crust.
For the egg wash, beat the egg and add 1 Tbsp of water. Brush this over the top of the pie. Sprinkle sugar, as desired.
Bake for 50 min, or until the crust becomes golden brown and the filling is bubbling. Cool for at least 15 min before slicing to let the filling set.
Notes
Make sure the sliced peaches aren't too drippy wet before using. Blot them with a paper towel to keep them fairly dry - they already hold a lot of water content that will keep everything juicy!
When you're working with the pie dough, if you're not using any part soon, refrigerate it for a bit to keep it chill.
With the extra filling liquid, you can cook it down to create a syrup. Just add it to a pot on medium heat and cook for about 15 minutes, and stir every so often until it thickens.
For the lattice, if there's hanging excess dough, I like to fold the bottom layer over the top, rolling in all the excess dough into a neat crust. Or you can cut off the extra length.