Egg White is a main ingredient in making mayo, and substituting mayo in a cake recipe will result in the moistest cake ever. If you tried a piece, you'd be like, "how...did you make this...so...?!" And then you'd be like, "...what?!" and I'd would be like, "What? Yea...that's what."
I'm all for ingredients I DON'T like being turned into things I DO like very much (cake!)
To me, it's just another example of all the wonderful ways God "uses ALL things (even those which are evil) for the good of those who love Him."