Of course you can prune it and save it- it's just a question of what it will look like for the next year or so.

Some people will save anything they can possibly save and others would replace it. It just depends on how important that site is to you aesthetically and how much you want to save it.

I'd remove all the dead portions and stare at it for a few months before I decided.
You?

looks telephone poled... planted too deep .. and there is a severe scar at soil level ...

as noted above... prune out the dead ... and see whats left.. and decide if you can live with it.. some can.. some cant ...

and pull back the soil... until you find the root flare ...

how long has it been there... if recent.. you might talk with the seller ...

ken

Pruning doesn't "save" a tree. In this case you'd be cutting off branches that the tree has already closed off so it doesn't matter to the tree if you leave them or cut them.

You can do a scratch test on each branch to see if the branch still has green cambium under the bark.

Let me put the question this way, assuming the other branches are dead, is there any way to prune it so it comes back as a reasonable looking Pawpaw tree?

It'll be fine. Prune off the dead stuff. In 3-5 years, you won't be able to notice anything was amiss - unless we have another tough winter that kills a significant amount of the canopy again.

I wouldn't worry about 'telephone poling' or trying to pull soil back away from the trunk to 'expose the root flare' - they naturally grow along creeks/watercourses where frequent deposition of silt is common. I can guarantee you that most of the native pawpaws growing here now have more soil against their trunk than they had when they first germinated or sprouted as root suckers. It's a non-issue for this species.