Preheat oven to 375°.
Using a non-stick cooking spray or butter, grease a 13x9 inch baking pan.
Combine brown sugar, spices, lemon zest and butter. Fill the cavity of each apple with the mixture. Any leftover filling can be pressed around the outside of the apples.
On a lightly-floured surface, roll out each pie crust circle slightly. Measure and cut a 7-inch square from each crust. This measurement is approximate. If you have something in your kitchen that is approximately that size, you can use it as a template. Repeat with remaining pie crusts. Re-roll leftover dough and repeat until you have your seven squares.
Place your filled apples in the center of each square. Lightly brush the edges of each dough square with the egg white and fold up over apples, pleating and sealing to dough.
Place dumplings in your prepared pan, not allowing them to touch each other.
Bake on the center rack of your oven for approx. 40 minutes or until golden brown.
Remove pan to a baking rack to cool. Spoon sauce over dumplings to serve.
Combine water, cornstarch and sugar. Stir until smooth and heat over medium heat until it comes to a boil. Boil until it thickens, stirring constantly. Remove from heat and add butter, lemon juice and lemon zest. Stir to mix. Serve warm over dumplings.