Preheat the oven to 325°F. Line with parchment (or leave ungreased) two baking sheets., Combine the flours, sugar, spices and salt in a food processor or medium mixing bowl., Cut in the shortening with a pastry blender, two knives or the food processor until the mixture resembles coarse crumbs., Mix in the water gradually, until the dough holds together in a ball but isn't sticky., Divide the dough in half and roll each piece out separately on a lightly floured surface to a 12" x 12" square, 1/8" thick. If the dough seems unusually resistant, just cover it with a towel and give it a 15-minute rest to relax the gluten., Use a sharp knife or a rolling pizza wheel to cut the dough into 1 1/2" squares, and transfer as many as you can at a time (a giant spatula works well here) to the baking sheets. Or, transfer each sheet of dough directly to the baking sheet with your spatula, rolling pin or hands, and then cut it into squares, separating the squares., Bake for 10 minutes., Remove the baking sheets from the oven, spray the tops of the crackers lightly with nonstick cooking spray and sprinkle with salt or garlic powder., Return the crackers to the oven and bake for 5 to 10 minutes more, until nicely golden brown. Transfer to a cooling rack., Store in an airtight container for up to a week, or freeze for up to a month.