Preheat oven to 180°C (350°F) and fold a 15 cm x 15 cm (7 inch x 7 inch) brownie pan with parchment paper.
In a large bowl, mash 3 ripe bananas. When completely mashed, add peanut butter and stir the mixture until smooth.
Sift in cocoa powder, give it a mix and transfer to the prepared brownie pan.
Bake in hot oven for 22 to 30 minutes - mine took 27 minutes. Let cool completely at room temperature before slicing.
