Perhaps the easiest way would be to make an encrypted backup (in iTunes) of your iPad mini, and then restore your iPod touch using the backup of your iPad.
As has already been stated, some apps won't be compatible and will not install, but everything else will appear.
The reason for using an encrypted backup is so that all of your passwords will also transfer, and you will not have to type them all in manually.
Alternatively, you can plug your iPod into iTunes and choose from your purchased apps in the Apps tab. Then Sync.