I am looking for a recipe like my grandmother use to make. She would use a yellow box cake mix but she would make this wonderful peanut butter frosting. I call it frosting, but I have no idea what she put in it. I have been looking for a recipe to make peanut butter frosting, but all I can't find one that says that you have to cook the frosting. I remember she would put the ingredients in a pot and would heat it up on the stove and then she would spread it on the cake. It was the best, so I was wondering if anyone has a recipe that would make a peanut butter cake like this. The most important step was cooking the peanut butter mixture. Any ideas?