Mississippi Mud Pie

Although I was born and raised in the Mississippi Delta, I never heard of a Mississippi mud pie or a Mississippi mud cake until I moved North and became food editor of The New York Times. It is conceivable that they existed, but no amount of research has revealed to me whether they did, or if these are recent creations that came about during my adulthood. Nevertheless, they are both rich as Croesus and many people find them delectable.