Preheat the oven to 200℃. Line a pound cake mold with parchment paper. Roast the walnuts. Combine the ☆ dry ingredients in a large bowl and mix with a whisk.
Dice 1/2 of a banana into 1 cm cubes. Mash the rest of the banana, then whisk into a purée.
Add the lemon juice, then the soy milk to the puréed banana, and mix until smooth.
Add the banana mixture to the dry ingredients, then add the walnuts, raisins, and diced banana, and mix briskly with a rubber spatula.
Pour the batter into the mold, then bake for 25-30 minutes at 200℃. When a skewer inserted into the middle comes out clean, it's done! If necessary, cover with foil to prevent burning the top.
Once it cools, remove it from the mold, take off the parchment paper, and let it completely cool on a cooling rack.
Here it is divided into 15 muffin cups. I baked them for 22 minutes at 200℃. They make great gifts.
Story Behind this Recipe
I modified a recipe from recipe author Ejima Miuta to suit my taste. The original recipe only used flour, a banana, and water, but I added raisins and walnuts, and increased the amount of banana to add more sweetness.
The key is to mix quickly after adding the banana, and to preheat the oven. Since the baking soda is activated by the lemon juice, if too much time passes between mixing it in and putting it in the oven, it may not rise. If you're worried about not working quickly enough, you can substitute the baking soda for 1 teaspoon baking powder. I used large bananas. You can use more or less as desired.