EzVPN is the simplest way to do it. What options are you after exactly, that aren't in a LAN-to-LAN configuration? The main issue with EzVPN in IOS is that you can't save a username/password in it, so you'll have to manually enter in the connect command every so often. Group password/configuration is saveable, which is the same as using a pre-shared key with LAN-to-LAN anyway.
