Prepare the filling by combining the cinnamon, flour, brown sugar, and vanilla in a bowl.
Roll out both piles of dough into flat sheets. Place one on parchment paper and sprinkle filling leaving 1 inch space.
Lay the second sheet of dough on top of the first. Crimp the sides with a fork and poke holes into the top of the pop tart.
Brush with egg wash or butter. Bake until golden. Add cream cheese, powdered sugar, cinnamon, and milk to make icing.