Does anyone have a recipe for this?

Unleavened in what way? No added leaveners such as baking powder...

Because if you literally want no leaveners, you wind up with only flour and water as ingredients .... (since eggs are leaveners).

Not really sure for this is a new request for me. Customer is asking for it so they can have it during a religious period. I looked online and those do have eggs, but never found a white cake. Most were chocolate.

Hi! Here's an angel food cake from a web site I just found... I don't know the origins of the site (i.e., kosher)...
http://www.carnegiemuseums.org/cmag/bk_issue/1997/marapr/dept4.htm

If I find others I'll come back and post.

Hi! Here's one for a Passover Sponge Cake:
http://judaism.about.com/library/2_cuisine/recipes_holidays/blpesachcakesponge.htm

And you may find something here:
http://kosher4passover.com/recipes-cakes.htm

Thanks for the info.