The photo also showed a cupcake version (not here, but at link). Cute!
I would use a whole egg so it would be "biscuit"(off-white)- colored.
http://allrecipes.com/Recipe/Simple-White-Cake/Detail.aspx?ms=1&prop25=112914617&prop26=WhatsCooking&prop27=2013-05-16&prop28=PhotoArea1&prop29=Photo_2&me=1
I would use a whole egg so it would be "biscuit"(off-white)- colored.
http://allrecipes.com/Recipe/Simple-White-Cake/Detail.aspx?ms=1&prop25=112914617&prop26=WhatsCooking&prop27=2013-05-16&prop28=PhotoArea1&prop29=Photo_2&me=1