In a bowl, mix the flour, sugar, salt, onion powder, garlic powder, and za'atar.
Stir in the water and 3 tbsp of olive oil and mix to start forming a dough.
Once the dough comes together, turn it out onto a floured work surface and work it until it becomes a ball. Add more flour if necessary so it no longer sticks to your hands as you work it.
Put the dough ball back into the mixing bowl and cover, letting it rest for about 10 minutes. There's no rise here, just resting.
Preheat your oven to 425℉, and line your baking sheet with parchment paper. Optionally, you can do the next step directly on parchment paper and transfer it to the baking sheet instead.
Working with half the dough at a time, roll the dough out to be nice and thin, aiming for 1-2mm. Once it's evenly thin enough, cut it into cracker-sized pieces using a knife or pizza cutter. Transfer these to the parchment-lined baking sheet with a bit of space between them.
Poke the crackers with a fork to prevent bubbling up or puffing. Brush them with the remaining olive oil, and sprinkle a bit of finishing salt (or more za'atar) over the top of them.
Bake the crackers for 8-15 minutes, depending on how thin they are. Aim for lightly browned. Remove them from the oven and let them cool to crisp up, and enjoy!