How do I re-record an individual PowerPoint slide with audio and transitions?

I felt like a genius when I realized I could copy the slide I wanted to re-record to a new PowerPoint, record the entire presentation (which is just one slide), and then copy and paste that back into the much larger presentation.

In PowerPoint it is possible to re-record a single (or multiple) slides in an existing series of recordings. By clicking on the dropdown option under Slide Show > Record Slide Show, and to choose for Record from Current Slide.... When the presenter view pops up, you can click on record, and re-record both the transition and audio (and even video if you have that enabled) for the current slide, and also any slides after that.

This keeps all slides that you do not touch (i.e. all slides that you do not revisit in presenter mode) intact, along with their timings, and previously recorded audio and video.

Even simpler, move the slide you want to re-record at the end of the presentation. Use the "record from Current slide" option, which will just record this last slide. Then move the slide back to its initial position.