Preheat oven to 400 degrees F. Line two baking sheets with parchment paper or silicone mat
Unfold puff pastry and lightly roll out on a floured work surface with a rolling pin, just enough to seal seams
Cut into 4 equal squares, about 5 inch.
Peel, core and dice apples and add to large bowl. Drizzle with lemon juice and toss to coat to prevent browning.
Add brown sugar, cinnamon and apple pie spice to the apples and toss to coat
Spoon apple mixture into the center of each puff pastry square
In a small bowl, whisk together the egg and water. Brush edges with egg wash.
Fold over edges to create a triangle. Use a fork to crimp the edges then place on baking sheet.
Cut a small slit or two in the top of the pastry. Brush top with egg wash. Place on baking sheet.
Bake for 16-18 min minutes or until golden brown.
Remove from oven and transfer to cooling rack for 5 minutes.
In the meantime, in a small bowl whisk together glaze ingredients, if using or cinnamon and sugar mixture, if using
Drizzle glaze or sprinkle cinnamon sugar mixture over turnovers.