Preheat the oven to 350 degrees. Coat a muffin tin with cooking spray.
Combine the diced peaches with the white sugar, brown sugar, cornstarch, vanilla extract, and cinnamon, mixing them gently.
Roll out the pie crusts on a floured surface, then roll them out with a rolling pin.
Use a cookie cutter or a ramekin to cut 4-inch circles out of the pie crusts.
Roll the leftover dough up into a ball, then roll it out with a rolling pin and cut out more 4-inch circles. I rolled my dough out very thin so I had enough to fill the whole muffin tin.
Place the circles (bottom crusts) into the muffin tin, pressing them firmly but gently, to the sides.
Scoop 2 tablespoons of peach pie filling into each tin.
Roll out the other pie crust and smooth it out using a rolling pin.
Using a sharp knife, cut out hearts and strips to cover the pies.
Top the pies with the crusts.
Mix the egg and water, and brush the tops of each pie with the mixture.
Place in the oven and bake for 30 minutes or until the crust is golden brown.