Chocolate & Peanut Butter Cupcake In A Mug 5 "Tasty!" Mrs Day 04 August 2017 I bought this for my husband who loves peanut butter. His verdict? Tasty! It is simple to use - my nine year old can follow the instructions easily - and turns out great. Personally, I prefer the (chocolate) cake in a mug but if you like peanut butter, you'll love this!