If you don't find a recipe, I do know that Publix and Food World are now making and decorating sf cakes, so I'm sure other grocery stores are doing them as well. Good luck! My daughter is also graduating next month! I feel like I'm losing my baby!
I just posted a load of Cake, Brownie and Frosting Recipes. I don't think I have a true white cake but I have several different frosting/cream cheese frosting recipes mixed in the bunch. I hope they can be of some help to you.
Jennifer