Does anyone have a good filling for a marble cake ? 

You could really do pretty much anything.  If you want to pump up the chocolate flavor, you could do a whipped ganache.  If you wanted to down play the chocolate you could always do a basic vanilla buttercream.  A white chocolate ganache would also be nice.  You could even do a strawberry filling since strawberries go well with both vanilla and chocolate.  Peanut butter mousse.  Caramel mousse.  Cookies and cream filling.  The possibilities are really endless.

This is for a sixteen year old girl, so I'm liking your " peanut butter mousse"......  THANKS for the suggestions....... That caramel sounds REALLY good also....hummm........

One of my most often requested filling for choco/marbled cakes was raspberry.  You can buy a 'sleeve' or use a good qualtity jam.  Another frequently requested one is Bavarian creme.

Ohhh, that raspberry sounds good ...... I usually use that with my white almond, but I'll bet it would be good with the marble also....... THANKS !

i think mocha buttercream rules on marble yellow/choc cake 

Oh, darn........ I was pretty much set on the peanut butter mousse, but this sounds FANTASTIC !

it's crazy good

Memphis, do you have a recipe I could steal ?

I just make a buttercream using some coffee for all or part of the liquid -- you could make a light chocolate bc and add the coffee -- no wrong way to make it

THANK YOU !  I'm going to try it !   :)