Peanut Butter Mug Cake is a simple treat for one which can be made in no time. I love these mug cakes as they are easy to bake & at the end you don't have any left overs to deal with. I used chunky peanut butter in this cake. For every spoonful of cake you get crunchy peanuts, which also gives a good bite to the cake. It's a perfectly soft & crumbly cake. Give it a try, sure you will be hooked.