It's pretty easy to do, tough to remember - just run this command from a terminal window:
hdiutil makehybrid -udf-volume-name <title> -o ~/Desktop/<dvd_name>.iso <location_of_video_ts_folder>
Replace:
'title' with what you want the title of the DVD to be (e.g. 'awesome_summer')
'dvd_name' with the image file name you want (e.g. 'awesome_summer')
'location_of_video_ts_folder' with where your VIDEO_TS folder resides (e.g. ~/Desktop/MyReallyAwesomeSummer)
That will create the iso file in whatever location you specified - in my example, I'd have a file called awesome_summer.iso sitting on my Desktop). Navigate to that file in finder.
Ctrl-click on the ISO and choose 'Open with...' then Disk Utility.
Click on the ISO name from the left-hand side of Disk Utility then click 'Burn'
