Preheat oven to 350°F.
In a bowl, mash bananas and mix in all of the wet ingredients until fully combined.
In a separate bowl, mix together all of the dry ingredients.
Add the dry ingredients into the wet ones; mix together well. The mixture will be tough to mix, but keep mixing until you get a fairly thick batter consistency.
Mix in walnuts and chocolate chips.
Line a muffin pan with cupcake liners and fill each cup almost all the way to the top with batter. Add a few more chocolate chips and walnut pieces to the top of each muffin.
Bake for 28-35 minutes or until a toothpick comes out clean.
Enjoy with a steaming cup of coffee or tea!