I thought this would be simple but I'm having trouble... I've made a couple lately and I used the method where you layer the mixes in the pan then use a skewer and gently run it through the mix. Well, the choc and white ended up blending... and only stayed marbled on the very outside. For my next attempt, I cooled the mixes in the fridge first to firm them up, so they wouldn't mix together so much. Then I just put some white, some dark... alternating to the top. DIDN'T mix with a skewer and they STILL blended together for the most part. My white chocolate mix is a lot runnier than my dark chocolate. Would that be the problem? I have my first wedding cake coming up and the bride wants marbled mud... UGH. HELP!

Bump.

I make a white chocolate raspberry swirl mud cake this way. I take out about a cup of batter and mix that with a cup of raspberry preserves. Then I drop small parts of that batter in with the white as I fill the pan. I finish by swirling with a knife. What I have noticed is that the two bake differently with the runnier raspberry mix not rising as much. So I had to cut back the amount I was using. It could be that if you are using equal amounts of batter to marble, then the different consistencies are really the problem. Based on my experiences, my suggestion would be to make a predominantly chocolate cake if that is your stiffer batter, and only add a small amount of vanilla cake to that. Good luck!

I'll have to see if I can find a less runny white chocolate cake recipe. Thanks for your tip. I will definitely try that next time! Something's got to work