Melt 1 tablespoon of butter in a medium saucepan over medium heat. Add the apples and stir to coat. Add the vanilla extract, lemon juice, brown sugar, cinnamon, nutmeg, ginger, and salt. Stir occasionally and cook 6-7 minutes, until apples begin to soften.

In a small bowl, whisk to combine the cornstarch and cold water. Pour mixture into the apples. Stir and cook for another 2-3 minutes until apple mixture thickens. Remove from heat. Allow to cool then puree using an immersion blender, blender or food processor. Puree til smooth.

Preheat oven to 375 F. Line a rimmed baking sheet with parchment paper. In a small bowl, prepare the egg wash by whisking the egg with 1 tablespoon of water. Set aside.

On a well floured surface, roll one sheet of pie dough or puff pastry into a 9" x 12″ rectangle. Carefully roll the dough around your rolling pin and then gently roll it out onto the prepared baking sheet.

Brush the edge of the crust with a 1-inch border of egg wash. Spread the apple filling evenly over the crust. Leave a 1 inch border.

Roll out second pie dough the same size as the first one. Carefully roll the dough around your rolling pin. Place the second crust over the bottom crust.

Gently press the edges of the dough with your finger tips to seal the top and bottom crusts together. Use a fork to crimp the edges. Use a fork or a toothpick to poke holes throughout the middle of the pop tart. These holes will allow steam to escape while the pop tart bakes.

Brush the pop tart allover with the remaining egg wash. Bake for 17-22 minutes or until golden brown. Allow the pop tart to cool on the baking sheet for a few minutes then carefully transfer it to a wire rack to cool completely.

Combine all the ingredients for the icing in a medium bowl. Whisk til smooth. The icing should be somewhat thick but a little runny so that it's easily spreadable. Spread the cinnamon icing over the cooled pop tart. Use a long, sharp knife to slice in 8 equal pieces.