Recipe from Penzey's Spices catalog. Yummy!
--Overnight soaking of the bread is what causes the dish to puff up and be very creamy when baked. If you don't have overnight, at least let it soak a few hours.
"Take a chocolate brownie layer topped with marshmallows, toasted pecans and chocolate frosting. Sound like the great makings for a dessert? Well it is what makes these Mississippi Mud Bars"----realmomkitchen.com