This is stupidly complicated, ill forgive you if you don't understand some of the moves. I made this puzzle using an engine, so its quite advanced =) theres an easy one from a variation i tried to branch out on but failed, due to that move =P find it for black =) Enjoy.
Oh there are some alternative moves, but i THINK these are the strongest ones, even if by slightly. If your engine says another answer, you can post the variatioin on. Whites still winning anyway =)