Let's say I have a star 20x the mass of the sun. At the end of its life, it collapses into a black hole. Now correct me if I am wrong, but as it collapses it rotational speed dramatically increases doesn't it? So does the singularity continue spinning as it forms? Can something spinning so rapidly actually become a singularity or would it become more of a torus?
Spinning black holes are governed by the Kerr metric, and have a ring singularity or "ringularity". A ringularity has a finite radius but no thickness so would not be described as a torus.