In a large bowl, mix together the flour, sugar, and salt. Cut in the chilled butter using a stand mixer, a food processor, or a pastry blender until the butter is evenly distributed but still in large, visible pieces. Add the ice water all at once to the flour and butter. Mix the dough just until it begins to come together (if using a stand mixer or a food processor, be especially careful not to overmix the dough). Gather the dough with your hands -- don't worry if you see streaks of butter -- and shape it into two disks. Wrap the disks in plastic and refrigerate for at least 1 hour.