Chocolate Peanut Butter Banana Cake

My roommate M loves chocolate and peanut butter. She can eat a jar of PB in a week. She is constantly buying jars of PB to make PB cookies but the PB never quite makes it past her mouth to cookie form. So I thought she would like a cake that combined two of her favs. Plus I just discovered how awesome chocolate and bananas are together. I've been missing out all these years! I found this cake on my heroine Tartlette's site.