Preheat your oven to 375 degrees
In a large bowl, mash 2 large very ripe bananas until smooth
Add 1 large egg, 2/3 cup of apple sauce, 1/3 cup of honey or maple syrup, 3 tablespoons of a neutral oil and a teaspoon of vanilla extract and mix until fully combined
Add 1 1/3 cups of all purpose flour, 1 teaspoon of baking powder, 1/2 teaspoon of baking soda, 1/2 teaspoons cinnamon, 1/4 teaspoon of salt and 1/2 cup of roughly chopped walnuts and mix until just combined
Fold in 2/3 cup of dark chocolate chunks until evenly distributed
Line a standard sized muffin tin and divide the batter between the cavities filling them close to full
Bake the muffins in a 375 degree oven for about 20 minutes or until a toothpick come out of the center of a muffin clean
Transfer the muffins onto a cooling rack to cool
Store leftovers at room temperature in an airtight container