Heat oven to 375° F. Lightly coat a baking sheet with vegetable cooking spray. Unfold the piecrust and place on sheet. Place the cinnamon apples in the center of the crust and mix in the lemon peel. Fold the edges over the filling, making pleats as you go. Brush the edges with the egg; sprinkle with the sugar. Bake 20 minutes or until the crust is golden. With a spatula, transfer from baking sheet to a platter. Serve warm or at room temperature.
With a bit of your own ingenuity, this can be great. I used Pillsbury flat pie crust. I also couldn't find frozen apples anywhere so I made my own. I cut up one of every kind of apple that I could find and coated them in cinnamon and froze them overnight. Then I partially thawed them and put them in the recipe. Also, I had to bake the crust for way longer than 20 minutes. I covered the top edges of crust once they were brown (20 min) and then baked for 5 minute intervals for another 20-25 minutes. It was absolutely delicious. Lots of compliments at thanksgiving. Plus I added cinnamon sugar on top instead of regular sugar.