There are two VERY crappy quality vids, but it's better than nothing!
http://hollywoodlife.com/2015/05/15/nina-dobrev-caked-vampire-diaries-crew-last-day-prank-instagram-videos-pics/

Maybe someone else can find a better vid???

Well, it happened almost 2 years ago.... If there were better quality videos out there, they would've surfaced by now.

I seriously think she's one of us. Check out this video where she ties up a guy and pies him: https://www.youtube.com/watch?v=LcBEeGba5UQ

Coincidence?

Yes.

Now if you want to start a conspiracy theory for why the clips of Nina getting caked look like they're shot by a blind elephant in pitch darkness with no flash... While the clip of her pieing a guy is shot in loving HD closeup with perfect lighting....

I'm down with that.

Here are some good pics:

http://www.usmagazine.com/entertainment/news/nina-dobrev-had-cake-fight-after-filming-last-vampire-diaries-scene-2015155

You can see the cake fight footage around the 3:30 mark in this video:

https://www.youtube.com/watch?v=9i7HMa0c-gY