Does anyone have a moist peanut butter cupcake recipe? I haven't been able to find a good one yet.

http://allrecipes.com/recipe/peanut-butter-sheet-cake/detail.aspx

The batter will be runny. Bakes up very moist and fluffy. I sub all butter instead of butter and oil. It's best liked with a chocolate buttercream or ganache, 

Thank you!!