I've never made a Guinness chocolate cake, but want to for my boyfriend's birthday. I have a few questions. First, is it carvable and/or stackable? I plan to dowel it, but I really want it to be a 3D bottle of Guiness (or maybe a draft beer, haven't decided) and want to be sure it's not too soft. Next, I'm wondering which recipe to go with. Doctored mix or scratch - which one does everyone prefer? And finally, fillings. I want to do one with a peanut butter filling (either ganache or buttercream or mousse), one with chocolate, and one with either plain buttercream, raspberry, or kahlua something. Does the Guinness cake end up tasting totally different - would it be weird with those fillings? Thanks!