Lay out frozen Puff Pastry on a greased or spray oiled sheet of aluminum foil. Allow it to mostly thaw and come to room temperature. Spread the ½ Stick of soft butter over the entire top surface. Use more butter if necessary.
Dump the entire can of apple pie filling on the Puff Pastry. This has to be roughly down the middle of the long dimension. Prior to baking you will be folding the pastry dough in half to create a 8x24 baking dimension. Do not fold yet! Keep the filling about 1 inch away from all edges.
Spread the filling the best you can over half the puff pastry avoiding the edges.
Mix the Sugar, Cinnamon, and salt together. Sprinkle that sugar mixture over the apple filling.
I use (4) 1 oz foil packs of cream cheese for the next step. You could cut a softened 8 oz brick of cream cheese as an alternative. Nothing says you can't use 8 oz and use up the cream cheese. In my case I lay a 4 oz ribbon of cream cheese down the center of the filling from side to side.
Once the pastry is completely thawed and foldable without cracking, fold the pastry over the top of the filling on to itself to create a pocket. Use a fork to seal the top dough to the bottom dough on both ends and the long edge.
Cut some vent strips through the top of the Puff Pastry using a wet sharp knife.
Slip the aluminum foil onto a cookie sheet.
Bake in a preheated 375°F for approximately 30 minutes or until golden brown and flaky.
Once baked slide the pastry and foil off the hot cookie sheet onto a wire rack to cool.
While the pastry is baking prepare the icing.
Mix the softened butter, orange juice, and vanilla together in a small but kind of deep bowl. Using a spoon, start beating small amounts of powdered sugar in by hand.
Continue adding and beating in powdered sugar until you obtain a desired stiff, but pipe-able icing. Adjust to taste. If adding any additional liquid, do so in very small amounts. Then beat in additional sugar to get a stiff consistency.
I then move the icing into a quart sized freezer zip lock. Snip one of the corners off with scissors, and this becomes a disposable piping bag.
Once the baked pastry has cooled some, pipe the icing across the top.