Start by making the croustade dough: In a large mixing bowl, mix together the flour, sugar, Morocco spice and salt. Cut in the cold butter until completely incorporated and the mixture resembles the texture of coarse sand (you can either do this by hand or pulse the mixture in a food processor). Add in the water and mix until everything comes together to form a cohesive dough. Chill for at least 15 minutes, up to overnight.\nMeanwhile, mix all pie dust ingredients together and set aside until ready to assemble. \nRight before assembly, make the peach filling by gently tossing the peaches with sugar, cornstarch and salt. Set aside.\nTo assemble: Divide the dough in half. On a lightly floured work surface, roll each ball of dough into a 7-inch circle. Evenly divide the pie dust among the center of the two circles of dough, followed by the peach filling. Fold up a small section of the dough as if you were pleating the crust and continue until all of the dough is pleated. \nBeat the egg with 1 tablespoon of water in a small bowl. Brush the outside of the croustades with egg wash and sprinkle with a pinch of coarse sugar. Transfer the croustades to a parchment-lined baking sheet. Place in the freezer while your oven preheats to 350 degrees. \nBake for 35-40 minutes, until golden brown and fruit juices begin to bubble up. Let cool slightly before slicing and serving.