In a small bowl, mix together the pumpkin puree, brown sugar, pumpkin spice, cinnamon, and salt. Set aside.
Assemble
Roll out the pie dough on a lightly-floured surface into a rectangle shape. Use a pizza cutter and a ruler to cut the dough into 2½"x3½" inch rectangles. Repeat with the other pie dough. You'll need a total of 16 rectangles.
On a baking sheet lined with a silicone baking mat or parchment paper, place one rectangle on and lightly brush it with the egg wash. Add ½ tablespoon of the pumpkin filling directly to the center of the dough and place another rectangle on top. Use a fork to crimp down all sides of the dough until fully sealed.
Repeat the step above until all 8 of your pop tarts have been formed. Place the baking sheet into the freezer while the oven preheats.
Preheat the oven to 400 degrees. Once heated, use a toothpick or a knife to gently poke holes on top of the dough and lightly brush it with the egg wash. Place the whole pan into the oven and bake for 12-17 minutes, or until they are golden-brown on top.
Pumpkin Icing
As the pop tarts are cooling, make the icing. In a small bowl, whisk together the powdered sugar, 1 tablespoon of milk, vanilla extract, and pumpkin spice until slightly thick (too thick and it won't spread, too thin and it will fall off). Add ½ tablespoon of milk at a time until it's the right consistency.
Once the pop tarts have cooled, drizzle the icing over the center and top with sprinkles. Allow the frosting to harden before serving.
Keep any leftover pop tarts in an airtight container at room temperature for up to 2 days or in the refrigerator for up to 4 days.
Notes
Pie Crust: If making your own dough, be sure to chill it in the refrigerator for at least 40 minutes and that it's covered in plastic wrap. If using store-bought, follow the directions on the box for knowing how far in advance it should be sitting at room temperature before rolling it out.Pop Tart Size: Use a pizza cutter and a ruler to cut the dough into a 2 ½" x3 ½" inch rectangle. You'll need a total of 16 rectangles.Pumpkin Spice: If you do not have pumpkin pie spice at home, you can easily make your own. Here is my recipe for how to make your own pumpkin spice.Icing: Wait until the pastries are completely cooled before drizzling on the icing.