I’ve actually made this pastry - in a cooking class in Connecticut. It is very time-consuming and you need A LOT of space. But they are absolutely delicious. Some time later I was changing planes in Rome and found them in a bakery/coffee shop in FCO and they were just as I remembered them.
10/3/2020 - I was able to find this at Presti’s Bakery in Cleveland’s Little Italy (and I am told it can also be purchased at Corbo’s a block away). I should say that at least at Presti’s, their sfogliatella is so popular that it sells out daily. When I visited on a Friday evening, they were out but the owner encouraged me to place a preorder for the following day, which I did. I am glad I did; it was delicious.