Preheat your oven to 350°F (175°C) and grease a loaf pan (8x4 inches) with coconut oil or line it with parchment paper for easy removal.
In a large bowl, mash the bananas with a fork until smooth. Add the applesauce, Greek yogurt, eggs, lemon juice, and vanilla extract. Mix until well combined.
In another bowl, whisk together the whole wheat flour, almond flour, baking powder, baking soda, cinnamon, and salt. Make sure all dry ingredients are evenly mixed.
Gradually fold the dry ingredients into the wet mixture, stirring gently until everything is just combined. Do not overmix to avoid a dense cake. Add the lemon zest and stir to incorporate.
If you’re using walnuts or pecans, gently fold them into the batter for a bit of crunch and added flavor.
Pour the batter into the prepared loaf pan and smooth the top. Bake for 45-55 minutes, or until a toothpick inserted into the center comes out clean. If the top is browning too quickly, cover it with foil towards the end of baking.
Allow the cake to cool in the pan for about 10 minutes before transferring it to a wire rack. Slice and serve once it has cooled completely. Enjoy with your favorite hot tea or coffee!