For the crust, in your food processor combine flour, salt, and one stick butter. Pulse until butter chunks are desolved into the flour and salt. Add the remaining butter and pulse again. It usually takes about three times. This time you are looking for your flour and butter mixture to have about pea sized balls. Next you will pour in the water and pulse only until the mixture begins to form a ball.
Once you have the crust created, sprinkle flour out on a clean serface and then roll out half of your pastry dough. Start by rolling it into a square, then fold down 1/3 of the way, and up 1/3 of the way. Fold in the sides 1/3 of the way. This will create a small saquare. Roll this out into a square, and repeat once again. On your last roll out, try to shape it into a circle. Place your crust into a pie pan that has been sprayed with cooking spray. Repeat the process with the top crust. Place in the fridge while you create the rest of the pie (between 1 to 2 hours is great).
Preheat oven to 375F.
In a saucepan over medium heat combine sugar, cornstarch, water and lemon juice. Cook over medium heat until it starts to thicken. Add in cherries and stir carefully until thick. Remove from heat and add vanilla. Let cool for a little while before adding to crust.
Remove crust from fridge and scoup in cooled cherry filling. Place crust on top. Combine egg with milk and whisk. Brush over the top of the crust, then sprinkle sugar on the crust. Bake at 375F for 20 to 30 minutes. Remove from oven once crust turns golden. Let cool, then serve and enjoy!