The title covers the basics.
I tried using testdisk but it also just sees the Optane as a ~3GB volume with no partitions. The 2TB HD doesn't even show up at all, anywhere - not in Windows, BIOS, or Testdisk.
Any ideas? I want to try and recover data from the HD if possible. I've since upgraded to a 2TB SSD and don't plan on re-enabling Optane due to this massive failure.