Mash bananas in large bowl. Mix in sugar and peanut butter. Once combined, add flour, salt and baking soda. Bake for 18-20 minutes or until a toothpick inserted in the center comes out clean.
While cupcakes are cooling, make frosting. Mash half a banana with a third cup of peanut butter. Add more peanut butter if necessary to make a thicker "frosting." Spread frosting onto cupcakes.
Recipe by The Emotional Baker at https://theemotionalbaker.com/banana-peanut-butter-pupcakes/