In a large bowl, combine both flours, powdered sugar, sugar and salt; mix in shortening. Add water and mix and knead the dough until it's smooth and supple, about 6 to 8 minutes. Divide into 12 (8-ounce) portions, shape each piece into a ball, flatten into a disk, wrap tightly in plastic wrap and refrigerate overnight or at least 2 hours.
Preheat oven to 400° F. Remove dough from refrigerator and flatten one piece with your hand on a floured work surface. Using a rolling pin, roll out as thinly as possible into an oval shape, dusting the surface as needed. (Alternatively, use a pasta machine to roll out the dough to attain a very thin sheet of dough.) Lightly oil the back of a cookie sheet or spray it with cooking spray.
Drape the thin sheet of dough over the back of the oiled pan. Brush with olive oil. Sprinkle with your choice of toppings such as cheese, seeds, fresh or dried herbs, garlic, cayenne, sea salt and pepper. Repeat with remaining pieces of dough.
Bake one at a time in preheated oven until deep golden brown and crisp. The time needed will depend on the thickness of the dough.
Cool and serve, breaking it into crisp shards.Makes 12 Breads Source: