Preheat oven to 350 degrees F.

In another large bowl, mix together the brown sugar, room temperature butter, remaining cinnamon, and vanilla.

On a flat lightly floured surface, roll out the pie crust to ¼” thick, and cut it into half. Set aside and roll out the other dough roll.

Lay rolled pie crust on a sheet pan lined with parchment paper or silpat with half of of the pie crust laying off the side of the pan.

Spread bottom half of the pie crust with the cinnamon sugar filling.

Fold over the top crust and crimp the edge with the back of a fork or pinch to seal with your fingers. As you seal the dough, be sure to press flat with your hands to remove any air in the tart.

In a small bowl, whisk egg until foamy. Using a silicone brush, baste the top of the tart with the beaten egg.

Using a toothpick, poke holes into the top layer of pie dough to allow steam to escape as it bakes.

Bake pop tarts for 8 minutes or until pie crust is golden brown. Remove from the oven and place on a cooling rack until completely cooled.

In a large bowl, mix together the powdered sugar, milk, ½ tablespoon cinnamon, and ½ tablespoon vanilla. Set aside and allow icing to dry completely.

Cut pop tarts into 12 square shape portions.