In a large bowl, whisk together the flour, arrowroot, sugar and salt. Cut in the butter with a fork or your hands until the flour is crumbly and the butter is well integrated.

Using a fork, stir in the water a little bit at a time (you may not need the entire cup) until the dough holds together. Knead it with your hands until it can form a smooth ball, then divide the ball in half, press each half into a disk, wrap in plastic wrap, and rest in the fridge at least a half hour.