Preheat oven to 400F (204C).
Lightly flour a clean counter and start rolling out the cold short crust pastry till about 1/4 inch thick (about 5 mm). Cut into equal squares. Or use a large cookie cutter shape to cut the dough. You want to make sure you have an even number of the same shape (so you have a bottom and a top for each pie).
Pair up your pastry squares or shapes into equal sized pairs for the top and the bottom. Spread out about 1 tbsp of apple butter into the middle of each of the 'bottom' halves. Place the 'top' onto the filled crust. Using a fork, gently press down on the edges to make sure they are well sealed all around.
Use a sharp knife to cut a 1 inch (2 cm) long slice into the top of each pie to allow steam to escape.
Place the pies on a parchment lined baking sheet, leaving some space between each pie to allow them to expand a bit.
In a small bowl, beat the egg till frothy. Using a pastry brush, brush the egg onto the top of each pie.
Bake for 20 minutes till golden brown on top.