Preheat oven to 180°C (350°F).
Mash the bananas and sweet potato until mostly smooth.
Add peanut butter, eggs, and baking powder. Mix well.
Fold in the walnuts and chocolate chips.
Transfer the batter to a parchment-lined loaf pan.
Sprinkle extra walnuts on top.
Bake for 50–55 minutes, or until set and golden brown.
Let cool for at least 20 minutes before slicing.
