Stir together apples and lemon juice. Sprinkle with brown sugar, 2 tablespoons of granulated sugar, and 1/2 teaspoon ground cinnamon. Let stand for 5 minutes for juices to release.

Heat butter in a saucepan over medium heat until bubbling. Add apple mixture and cook until apples are softened and juices are reduced, about 6-9 minutes. Stir in cornstarch and vanilla until thickened, about 1 minute. Cool for 15-30 minutes.

Roll out pie crusts and cut each into eight 4x2-inch rectangles. Place 8 dough rectangles on a surface and brush edges lightly with whisked egg.

Spoon 1 1/2 tablespoons filling onto each base crust, leaving a 1/4-inch border. Cover with remaining dough rectangles, stretching to align edges as needed. Crimp edges with a fork.

Preheat air fryer to 350°F for 5 minutes. Make 3 diagonal cuts on each pie for venting. Mix remaining sugar and cinnamon, and sprinkle on top.

Lightly coat air fryer basket with cooking spray. Bake 4 pies at a time for 14-17 minutes until golden brown. Repeat with the remaining pies.