1 1/2 cups all-purpose flour
1/2 cup chopped walnuts, optional
3/4 cup - 1 cup granulated sugar
1 teaspoon baking soda
1/2 teaspoon baking powder
1/2 teaspoon cinnamon
1/4 teaspoon salt
1 cup water or milk (dairy or non-dairy)
1 teaspoon white or apple cider vinegar or lemon juice
5 Tablespoons oil
1 teaspoon pure vanilla extract
1/2 cup mashed overripe banana (fresh or frozen - thawed)
1 overripe banana for coins on top, optional
1. Preheat oven to 350 degrees Fahrenheit. Spray an 8-inch square pan with nonstick cooking spray or line with parchment.
2. In a large bowl, whisk together the flour, walnuts (if using), sugar, baking soda, baking powder, cinnamon, and salt.
3. Add water/milk, vinegar, oil, vanilla, and 1/2 cup mashed overripe banana to dry ingredients. Stir with a spatula until combined and there are no pockets of dry flour.
4. Pour into prepared pan and smooth top.
5. If you are using the additional banana for the top of the cake, cut the banana into coins and place gently on the top of the batter, spaced evenly.
6. Bake 25-35 minutes, or until center is no longer jiggly and toothpick inserted into the center comes out clean. Cool completely before cutting for the best texture.