Add all the dry ingredients to a Food Processor and mix briefly.
Add the water and mix until the mixture forms a dough ball. It will be sticky/soft.
Turn out on a floured board and knead with enough flour to keep from sticking until it forms a firm ball.
Roll out the dough to desired thickness (I use about 1/4 inch).
Cut into squares of desired size and use a fork to pierce each square several times (3-4).
Place squares on a baking sheet on Parchment Paper. Set the baking sheet in a preheated 350 degree oven for about 30 minutes. Remove and turn the Hardtack. Return to oven for 10-15 minutes. Remove and cool on paper towels. You may want to adjust the temp and cooking times for your oven. The goal is to cook to a light toasty brown. The hardtack will be very hard, so nibble carefully.