Sorry I don't understand as the obstruction, in the scenario, only blocks the runway after you have descended below ACH - from that point on you state you are committed to land no matter what?
ACH = Asymmetrical
Committal Height. Although it may depend on aircraft type, in general a twin MEP running on only one engine will continue to descend, even on full power once fully configured for landing. If there is actually time to reconfigure the aircraft for a climb then I would suggest the ACH was not correctly selected in the first place (and should have been lower).
Including flying into the obstruction?!
Lots of options but, as with a Glide Approach in a single engine, going around is not one of them.
Land alongside runway (instead of on it), land on runway and hit obstacle at a slow speed whilst on the ground (rather than at a faster speed and still airborne), etc