In a large mixing bowl stir together flour and salt. Cut the cold butter into 1/2-inch-thick slices (not cubes). Add butter slices to the flour mixture and toss until slices are coated and separated.
Pour ice water over flour mixture. Using a spoon, quickly mix (butter will remain in large pieces and flour will not be completely moistened.)
Turn the dough out onto a lightly floured pastry cloth. Knead dough 10 times by pressing and pushing dough together to form a rough-looking ball, lifting the pastry cloth if necessary to press dough together. Shape dough into a rectangle (dough still will have some dry-looking areas). Make corners as square as possible. Slightly flatten dough.
Working on a well-floured pastry cloth, roll the dough into a 15x12-inch rectangle. Fold dough crosswise into thirds to form a 5x12-inch rectangle. Give dough a quarter turn; fold crosswise into thirds to form a 4x5-inch rectangle.
Repeat the rolling and folding process once more, forming a 4x5-inch rectangle. Wrap the dough with plastic wrap. Chill dough in the refrigerator for 20 minutes. Repeat rolling and folding process 2 more times. Chill dough in the refrigerator for 20 minutes more before using.
Using a sharp knife, cut the dough in half crosswise into 2 equal portions. To store the dough, wrap each portion in plastic wrap and refrigerate until ready to use or for up to 3 days. For longer storage, wrap each dough portion in heavy foil. Seal, label, and freeze up to 3 months. Thaw the dough, covered, in the refrigerator about 24 hours before using. Use the dough as directed in Mocha Filled Cream Horns and Banana Cream Napoleons in the Recipe Center.