Preheat your oven to 350°F (175°C). Grease a 9x5 inch loaf pan or line it with parchment paper for easy removal.
In a large bowl, combine the mashed bananas, Greek yogurt, brown sugar, honey, eggs, and vanilla extract. Mix until smooth and well incorporated.
In a separate bowl, whisk together the baking soda, baking powder, salt, cinnamon, and flour until evenly mixed.
Gradually add the dry ingredient mixture to the wet ingredients. Stir gently until just combined; do not overmix. If using, fold in the chopped walnuts and dark chocolate chips.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake in the preheated oven for 55-65 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove from the oven and let it cool in the pan for about 10 minutes. Then, transfer to a wire rack to cool completely.
Notes
Serve warm or at room temperature, sliced, with a spread of almond butter or a dollop of extra Greek yogurt on the side. Dust with powdered sugar for a beautiful finish if desired.