Is that folder still on the Desktop? If you open the Trash window do you see a Recovered Files folder? If so, then check there. Open your Home folder then open the Desktop folder and look there. Download EasyFind 4.9.3 and use to search for your folder or a file. It searches everywhere including places Spotlight does not usually search. It's not as fast as Spotlight but it's pretty fast.
If the files were deleted, then you may have a problem that will cost you money to find.
General File Recovery
If you stop using the disk it's possible to recover deleted files that have not been overwritten by using recovery software such as MAC Data Recovery, Data Rescue II, File Salvage or TechTool Pro. Each of the preceding come on a bootable CD to enable usage without risk of writing more data to the disk. Recovery software usually provides trial versions that enable you to determine if the software would help before actually paying for it. Beyond this or if the drive has completely failed, then you would need to send the drive to a recovery service like Drive Savers, which is very expensive.
The longer the hard drive remains in use and data are written to it, the greater the risk your deleted files will be overwritten. Unfortunately, these programs do not work on SSDs.
Also, visit The XLab FAQs and read the FAQ on Data Recovery.