Place cold cubes of butter into freezer until semi-frozen, about 20 minutes. Place flour, salt, softened butter, and 3/4 cup ice water in mixer fitted with paddle attachment. Combine on low speed until just combined . Remove bowl from mixer and add semi-frozen butter cubes. Using hands, quickly incorporate butter chunks into dough . Place dough onto large piece of plastic wrap and press into an 8- by 10-inch rectangle that is about 1-inch thick. Wrap tightly and chill 1 hour.
