Preheat the oven to 350 degrees F. Line a muffin pan with liners and spray the inside of the liners to prevent sticking.
In a large bowl, mix together mashed bananas, honey, egg, vanilla, olive oil and milk until well combined. Add in whole wheat pastry flour, baking soda, cinnamon and salt and use a wooden spoon to mix together until the batter is just combined. DO NOT overmix. Fold in ½ cup chopped walnuts.
Divide batter evenly into muffin liners, sprinkle each muffin with chopped walnuts. Bake for 20-25 minutes or until the toothpick comes out with just a few crumbs attached.
Cool muffins for 5 minutes then remove and transfer to a wire rack to finish cooling. Muffins are best served warm and even better the next day. Makes 12 muffins.
