Preheat your oven to 350 degrees F. Lightly coat 24 mini muffin cups with cooking spray.

In a medium saucepan, melt the butter over medium-high heat. Add the diced apples, brown sugar, cinnamon, and salt. Stir often and cook until the apples become tender, which should take around 10-12 minutes. Once done, mix in the lemon juice and set aside to cool.

In a separate bowl, combine the flour, brown sugar, and toasted pecans. Add in the butter and blend until you have a crumbly texture.

Roll out the pie crust on a floured surface using a floured rolling pin. Use a round cutter, around 3 inches in diameter, to cut out at least 24 rounds (12 from each pie crust, if store-bought).

Gently press each round into the mini muffin cups, shaping the edges with your fingers to form a pie crust. Brush the top edges with the egg wash.

Evenly distribute the apple filling onto the pie crusts in the muffin cups, then sprinkle the crumble topping on top.

Bake for 15-20 minutes or until the edges are golden brown. Let cool on a wire rack. Once cooled, use a knife to carefully loosen the cupcakes from the muffin cups.

Serve these scrumptious cupcakes topped with whipped cream, ice cream, or drizzled with caramel sauce for extra indulgence!