Instructions

1. Preheat the oven to 180°C (355°F) (without fan).
2. Line a loaf pan with a 1 litre (4 cup) capacity with baking paper.
3. Place the peanut butter into a small saucepan and heat gently over a low heat, just until it has warmed through and has become runnier in texture. Set aside to cool slightly while you get on with the rest of the recipe.
4. Measure the flour, baking soda and salt into a bowl.
5. Cream the butter and sugar together using a stand mixer or electric beaters.
6. Add the vanilla extract.
7. Add one egg, followed by a tablespoon of the flour mixture. Beat until everything is incorporated.
8. Add the second egg, and then slowly beat in the rest of the flour mixture.
9. Mash the ripe bananas and add this to the batter.
10. Mix everything together.
11. Stir through the chocolate chips.
12. Pour the warmed peanut butter into the batter, and use a wooden spoon to gently marble it by folding it through once or twice. You don’t want to fully mix the peanut butter into the batter.
13. Pour the batter into the loaf pan.
14. Slice the firm banana in half lengthways and arrange it on top of the batter.
15. Bake for about 1 hour, or until a skewer inserted in the middle of the cake comes out clean. The baking time will depend on the shape of your loaf pan – some are wider or taller than others.
16. Remove the cake pan to a wire rack to cool for about 10 minutes, before carefully unmoulding the cake and letting it cool completely on the wire rack.
17. Serve warm or at room temperature.