01 - Preheat the oven to 350°F and line a 12-cup muffin tin with paper liners or grease lightly with cooking spray.
02 - In a large bowl, mash the ripe bananas until smooth. Whisk in eggs, Greek yogurt, honey, oil, and vanilla extract until well combined.
03 - In a separate medium bowl, whisk together the whole wheat flour, baking soda, baking powder, cinnamon, and salt until evenly distributed.
04 - Gradually add the dry ingredients to the banana mixture, stirring gently with a spatula until just combined. Do not overmix as this will result in dense muffins.
05 - Gently fold in the chopped nuts and optional dark chocolate chips until evenly distributed throughout the batter.
06 - Divide the batter evenly among the prepared muffin cups, filling each about 3/4 full to allow for rising during baking.
07 - Bake for 18-22 minutes, or until a wooden toothpick inserted into the center of a muffin comes out clean and the tops are golden brown.
08 - Allow muffins to cool in the pan for 5 minutes before transferring to a wire rack to cool completely. This prevents them from becoming soggy.