In medium bowl, mix 2 1/2 cups flour and 1/2 teaspoon salt. Cut in cold butter, using pastry blender, until particles are size of peas. Sprinkle with water, 1 tablespoon at a time, tossing with fork until flour is moistened. Shape dough into a ball. Divide dough in half; shape into flattened rounds. Wrap in plastic wrap; refrigerate 45 minutes.