Preheat oven to 180. Line two baking trays with baking paper.
Combine butter and peanut butter in a small saucepan over a medium heat. Cook, stirring frequently for 3/4 minutes or until melted and well combined. Allow to cool for 5 minutes.
Add the cooled butter mixture to the brown sugar and egg and mix well. Add combined sifted flours, oats, chocolate chunks and cranberries. Mix well to combine.
Roll 2-3 tablespoons of the mixture into a large ball. Place onto prepared trays and flatten slightly. Bake 12-14 minutes or until golden and firm to touch. Stand for 5 minutes on the tray before transferring to a wire cooling rack.
Notes & Tips
These are a truly decadent treat - and you can honestly say you only ate one cookie!