Preheat the oven to 190 ºC. Place one of the crusts in a tart pan and lightly prick the base with a fork.
2.
Cut the cherries into pieces. In a bowl, mix it with the brown sugar, balsamic vinegar, vanilla, cornstarch, and cinnamon. Let it sit for 10 minutes so it can release its juices.
3.
Pour the filling over the crust and spread it evenly.
4.
Cover it with another layer of the pastry or slice it into strips for a nicer finish. Seal the edges.
5.
Brush the surface with the beaten egg and make a small cut in the center to allow steam to escape.
6.
Bake the tart for 40-45 minutes until the pastry is golden brown and the filling is bubbly. Let it cool to room temperature before slicing.