What is your suggested solution for the threat of website UI spoofing?
The key to this problem is identifying some difference between a request to the real site and a request to the spoof site.
The simplest difference is some cookie-based UI preference. A cookie set on your (real) site will only ever be returned to your site, and will never be sent to a spoof site.
Now there are plenty of reasons that the valid cookie might not be sent to your site, the user might be using a different computer or they might have expired/deleted cookies, but at least you can guarantee that it won't be sent to the spoof site.