Preheat oven to 350°F and grease a cast iron loaf pan with coconut oil.
Combine flour, baking soda, salt and nutmeg in a small mixing bowl.
In a separate mixing bowl, use a hand mixer to combine the rest of the ingredients minus the chocolate chips and walnuts.
Slowly add dry ingredients to the wet ingredients while continuing to mix with the hand mixer.
Once everything is well combined, quickly stir in chocolate chips and walnuts.
Transfer to the loaf pan and bake on the center rack for approximately 1 hour 20 minutes.
Notes
Baking time will vary by oven. Keep an eye on the bread, and after about 55 minutes, if a knife stuck in the middle of the bread still comes out with dough, cover with aluminum foil to keep the top from overcooking.
It may take up to an hour and 15 minutes to cook through.
Banana bread will last for up to 3 days at room temperature or up to 1 week when stored in an airtight container.