Preheat the oven to 450˚F and line a sheet pan with parchment paper.

In a medium bowl, stir together the flour, sugar, and salt.

Add in the water and olive oil and mix with a spatula until a shaggy dough forms.

Turn the dough out onto a clean surface and knead the dough for about 5 minutes, until the dough is smooth and elastic.

Cover the dough with a clean kitchen towel and let it rest for 15 minutes.

Divide the dough in half. Using a rolling pin, roll out the dough until it's about 1/16th of an inch thick. You shouldn't need flour, but if the dough starts to stick, you can use a light dusting. 

Using a Christmas tree cookie cutter, cut the dough into tree shapes as close together as possible (this dough does not re-roll very well). Transfer the cut trees to the baking sheet. Use a fork to pierce each cracker a few times (to keep them from puffing up too much in the oven). 

Use a basting brush to brush each cracker with a light layer of olive oil, then sprinkle the crackers with a bit of flaky salt. 

Bake the crackers for 6-8 minutes.  Rotate the tray halfway through to ensure even baking. They are done when they start to lightly brown and crisp at the edges. Keep a close eye on the oven as they can burn quickly.

Remove from the oven and let them cool completely on the sheet pan. They will harden more as they cool.