Preheat oven to 375˚F and line two baking sheets with parchment paper or silpat.
Add both flours, salt, sugar, garlic powder, rosemary, olive oil and water to a bowl. Use a fork to mix until a shaggy dough forms, then turn the dough out onto a clean surface.
Knead the dough with your hands for about 5 minutes, until it forms a smooth ball. Divide the dough in half.
Roll out each half into a large rectangle, about 1/16-inch thick (it should be very thin).
Using a fluted pastry cutter (or a knife), cut the crackers into thin rectangles about 6 inches long and 1 ½ inches wide.
Carefully transfer to the prepared sheet pans. Sprinkle the tops with flaky salt. Bake for 12-15 minutes, until the bottom is golden brown. (The baking length will depend on how thin you rolled your dough).
Let cool completely before enjoying.
