Well, if it takes a pasta machine, I will not be getting that result. I am not sure that a completely hollowed out roll is desirable, or even that tasty. I am in quest of the golf-ball-sized hole, surrounded by bread.
I need to try the recipe again, this time using only King Arthur flour. I think that there is something to how the ball is shaped, as well as the stamp, to get a good result. Perhaps, I can give it another try after Thanksgiving.
I don't plan to try the pasta maker, either, but the extended biga period makes some sense. I've never seen anything on Italian shaping techniques for rosetta rolls, so maybe they are flattened and folded at some point.