Preheat oven to 425˚ F.
Roll out the pie crust into an even circle. Cut a slit half way through the pie crust.
In the bottom left fourth of the pie crust (next to the slit), add about 1/4 cup of apple pie filling. Be sure to leave clost to an inch of pie crust around the outer edge.
In the section above that, add a layer of caramel sauce. Top the caramel with Reese's pieces.
To the right of the Reese's pieces, add another section of apple pie filling.
In the bottom right fourth of the crust, add a layer of graham crackers.
Take the bottom left section with apple pie filling, and fold it up and over the section with the Reese's pieces. Pinch the outer pie crust to seal it together.
Fold that top left section to the right over the pie filling. Pinch the outer crust together.
Fold that top section down over the graham crackers. Pinch the outer crust together. Fold and press the outer crust down under the pie. Cut a few slits in the top of the pie.
Line a baking sheet with parchment paper. Transfer the pie to the baking sheet.
Brush the top and sides with a thin layer of milk. Brush the bottom seam (next to the layer of graham crackers) with milk. Gently press the seam to seal the pie. Try not to tear any crust.
Mix the sugar and cinnamon together. Sprinkle the pie with the cinnamon sugar.
Bake for 30 minutes.
Slice into 4 pieces