Oh, you are a dreamer. One click restore, we all dream of that. Reality is:
1: Use "pkgbackup" from Cydia to backup all your Cydia apps, you can save it to your contacts or dropbox. DropBox is probably the best solution. It saves a list of apps that you have on your iPhone.
2: When you have to restore for whatever reason, first restore from iTunes.
3: Jailbreak again.
4: Go to Cydia and download "Pkgbackup" again and install it.
5: Open Pkbackup and go to wherever you saved your backup, Contacts or DropBox. If you used DropBox you may have to install DropBox first.
6: Tell PkgBackup to restore from that backup. It will look at your list and try to download all the apps you have in the list and install them. You may still have to download and install a few apps separately.
No matter how you do it, it's a PITA to do a complete restore.
Another thing to do is download the "AppInfo" app from Cydia and send yourself an e-mail with all of your installed Cydia apps listed from the app. This way you will have a list of all the current apps, so you can be sure they have been re-installed during the restore.