For you delilah:
http://www.chefs.com/recipes/19680_1+-+Mayonnaise+Cake.aspx
I wish I could get my Nana's recipe. It's hard for me to talk to Mom right now though. She makes it too!
They made the peanut butter icing from scratch as well.
I don't even like cake and I love this!
Good luck!
Renee, you are tremendously talented! Keep it up!