Cake wins if it has buttercream frosting. If it's a cream cheese based frosting, pie wins. Sorry, that's just the way it is.
I love red velvet cake, but only if it's sweetened with beet sugar and NO COCOA POWDER (beet sugar is the correct recipe, of course). And I can't stand the cream cheese frosting!! So, yeah, the buttercream frosting isn't "authentic" on a red velvet cake, but who cares?