Using a food processor, combine All-Purpose Flour (3 cup), Baking Powder (1/4 teaspoon), Salt (1/2 teaspoon). Add Unsalted Butter (1 cup), Vegetable Shortening (2 tablespoon) and pulse in short bursts. Add 3 tablespoons of Water (5 tablespoon) and pulse 5-6 times. Add 2 more tablespoons and pulse 2-3 times.
Start to check the consistency of the dough, it should hold together when you pinch it between two fingers without being overly crumbly. Add ice water a little at a time, pulsing 2-3 times after each addition until you achieve the consistency of crumbly Play Doh.
Transfer the dough into a large bowl and use your hands to form it into a ball. Cut the dough in half, form into two balls and flatten each into a 8" disc. Wrap the discs in plastic wrap and refrigerate for an hour.
In a saucepan, combine Peach (4), Brown Sugar (2 tablespoon), Bourbon (1 1/2 tablespoon). Bring to a boil, reduce heat to a simmer annd stir until the sugar is dissolved.
Add the Arrowroot Starch (1 tablespoon). Stir until thickened. Remove from heat and stir in Bourbon (1 tablespoon).
Preheat the oven to 350 degrees F (180 degrees C).
Generously flour a work surface. Cut one of the discs in half lengthwise and return the rest to the refrigerator. Roll out the pastry to a rectangle and about 1/4" thick. Trim the rough edges and cut the pastry with a pizza cutter into 3 1/2".
Spoon a generous tablespoon of filling into the center of the dough.
Using a pastry brush, brush Egg (1) along the edges of the pastry. Fold the dough over and press a fork along the sides. Transfer the pie to the baking sheet. Cut a few vents about 1/2" long. Brush the pies with Cream (1/4 cup) and sprinkle with Demerara Sugar (1/4 cup)
Bake in the center of the oven for 20 minutes.
Rotate the pan 180 degrees F (80 degrees C) and continue to bake for an additional 10-12 minutes. Remove from oven and cool to room temperature. Continue with remaining pies.
While pies cool, mix Powdered Confectioners Sugar (1 cup) and add Cream (2 tablespoon) in a small bowl until smooth. Drizzle the pies with the glaze and let dry about 15 minutes.