Place your bowl on your scale and zero it out. Measure out the flour until your scale reaches 12.5 oz. Add your salt & sugar, then add your frozen butter pieces. You can either premeasure, cut and freeze your butter, or cut your butter after its frozen. (Much easier to cut AND THEN freeze).
Throw all of this into a food processor. A blender will work, but not as well. And you can always cut the butter into your flour with a pastry cutter, but that takes a long time and your butter may not stay cold.
Your mixture should resemble course sand. Pour the mixture into a bowl and add your water. Once the water is incorporated dump the mixture out on a board and knead the dough just enough to form a dough ball. Chill mixture for at least one hour. (you want that butter cold and in visible chunks.)
* If you choose the mini food processor, you will need to blend your dough in two batches.