I was wondering if any of you wonderful cooks had a good choc. marble recipe. I have a request for a 2 layer sheet cake. I'm planning on doin' a fbct on top of the cake. I need a durable cake that will hold up to the layering. I have the recipe for the Cake Mix Doc choc. marble. Has anyone tried that one?
thanks!!

I use the Yellow cake recipe from the cake mix doctor but leave out about a cup of batter and mix in some melted semi sweet chocolate. I tried adding cocoa but the chocolate part came out bitter.