We are still freaking out over this!
Check out both shots in the gallery (above)!
[Image via Annie Leibovitz/Vanity Fair.]
This sh*t is bananas, B-A-N-A-N-A-S!
The No Doubt frontwoman performed Hollaback girl alongside the Happy singer and it definitely brought back AH-Mazing memories of their past collaboration!
We wouldn't be surprised if Gwennie and Pharrell teamed up for another catchy hit again!