Place the pie crust on a lightly floured surface. Roll the crust out into a 12 inch circle. Use a 4 inch cookie cutter to cut out 6 of your desired shapes. Transfer the shapes to a sheet pan lined with a silicon baking mat or parchment paper.
Sprinkle the cheese evenly over the 6 crust shapes. Top with slices of pepperoni to cover, leaving a small border around the edges.
Beat the egg in a small bowl. Brush the egg along the border of the dough.
Gather the dough scraps and re-roll the dough to a similar thickness. Cut out 6 more of your shapes. Lay the shapes on top of the pepperoni layer. Use a fork to crimp the edges shut.
For a standard pizza pocket, use a paring knife to cut a few lines in the top. For a jack-o-lantern, use a paring knife to carefully cut out eyes and a mouth.
Brush the tops of the pizza pockets with the egg wash. The pockets can be baked immediately or covered loosely with plastic wrap and stored in the fridge.
Bake the pizza pockets for 15-20 minutes until golden brown. Serve immediately with marinara sauce for dipping.
Make Ahead: The uncooked pizza pockets can be stored loosely covered in the fridge for up to 8 hours.