Upvote:3
Skiplagged allows you to search based on layover stop, especially if your destination is flexible.
Note: Airlines don't especially like the basic idea behind the site, of people buying connections they don't intend to use, to get lower overall fares, because it messes up their financial models based on route competition, even though they wind up selling more tickets than the actual work they'll have to do to support customer travel. Recognize that failing to travel on any leg can lead to e.g. cancellation of the rest of the legs on that reservation.
Upvote:3
Since you know you want to go to SLC, why not:
This also gives you the option of taking a longer pause in SLC.
Upvote:7
You want to pick the "Multi City" option on most flight search engines.
I just checked on SkyScanners multicity option for flights from ATL to SLC on 1st Dec and then from SLC to HNL on 2nd Dec, returning from HNL on the 30th Dec and got lots of results.