This starts off with her actual voice then I reduced the pitch.
Many female singers sound like guys with real good voices when the pitch of their voice is digitally reduced by around 4 semitones.
Here’s another:
There’s (unsurprisingly) a bit of an autotune effect in the manipulated voice.
But yeah, all you’ve basically found is that the same qualities that make a woman’s voice sound good also make a man’s voice sound good. I’d expect that it’d work even better going the other way, since a stepped-down female voice is necessarily missing some overtones.
I’m on the road right now, but when I get home Sunday I’ll post an old remix of mine to this thread.