Pumpkin spice poptart bars

1. Preheat your oven to 350F.
2. In a large bowl, combine butter, brown sugar, and powder sugar. Mix until the butter and sugar are creamed together; you can mix by hand or with a stand/power mixer for ease.
3. Add in the egg and vanilla and mix again.
4. Add in the flour and cinnamon and mix until a dough forms. It may seem dry at first but keep mixing.
5. Split your dough in half. Add one half to a lined 8x8 baking dish and press it until it is flat.
6. Take the other half of the dough and press it into an 8x8 square on a piece of parchment paper.
7. Make your pumpkin spice filling by mixing all the filling ingredients (brown sugar, pumpkin puree, vanilla extract, cinnamon) in a small bowl.
8. Add the pumpkin spice filling to your 8x8 baking dish, spreading it over the first layer of dough.
9. Top with the other half of your dough (the one pressed on parchment paper).
10. Bake in the oven at 350F for 40 minutes.
11. Allow your poptart bars to cool for 15 minutes.
12. While cooling or once cooled, prepare the icing by mixing powder sugar, vanilla, cinnamon, and milk until smooth.
13. Ice the cooled poptart bars and enjoy!