Roll out one pie crust into a 12 inch circle. Cut into 6 3x4 inch rectangles, rerolling the dough as needed. Repeat with the other crust. Whisk the egg with 1 tablespoon of water until smooth.
Arrange half of the dough pieces on a work surface and brush with the egg wash.
In a small bowl stir, together the brown sugar, cinnamon, and flour until combined.
Sprinkle the brown sugar mixture evenly between each piece of dough, about 1 1/2 tablespoons each, leaving a gap around the edges.
Top with the remaining pieces of pie crust and use a fork to crimp the edges to seal. Brush the tops with the egg wash.
Place in a 350 degree preheated air fryer for 8-10 minutes or until golden brown. You will need to work in batches so as not to overcrowd the air fryer.
Remove from the air fryer and let cool before glazing.
To make the glaze, whisk together the powdered sugar, cream, vanilla, and cinnamon. Add additional cream to thin the glaze to your desired consistency.
Spoon the glaze over the tops of the cooled tarts and let set for 15 minutes before serving.
Notes
To warm, place in the air fryer for 1-2 minutes at 350 degrees.