Preheat your oven to 425°F (220°C).
Prepare the cherry filling: In a medium bowl, combine cherries, sugar, cornstarch, vanilla extract, and lemon juice.
Roll out the pie crust on a floured surface and cut into circles for the pies.
Spoon a heaping tablespoon of cherry filling onto one half of each dough circle.
Fold the other half of the dough over the filling and crimp the edges to seal.
Place the pies on a baking sheet lined with parchment paper and brush the tops with beaten egg.
Bake in the preheated oven for 20-25 minutes or until golden brown.
Allow the cherry pastry pies to cool for a few minutes before serving warm or at room temperature.