Preheat oven to 350°F. Spray a 9-by-5-inch loaf pan with cooking spray.

Place goji berries in a small bowl and cover with water to soak for about 5 minutes.

In a large mixing bowl, whisk together the flour, tiger nut flour, baking soda, cinnamon, and salt.

In another mixing bowl, mash three of the bananas. Add the eggs, melted butter, brown sugar, yogurt, and vanilla. Fold the banana mixture into the flour mixture. Drain and dry the goji berries, save a few for the top of the loaf and add the rest to the batter. Do the same with the walnuts. Pour the batter into the prepared loaf pan.

Cut the last banana in half lengthwise and place on top of the batter, scatter some goji berries and walnuts and bake for 60 – 70 minutes or until a toothpick inserted into the center comes out clean. Let cool in the pan for 10 minutes then remove to a wire rack to finish cooling.