Preheat oven to 350 degrees. Grease a loaf pan well.
Whisk flour, baking powder and baking soda in a bowl.
In a medium saucepan, combine applesauce, cinnamon and sea salt. Cook, stirring constantly, over medium high heat for 3 to 4 minutes. Stir in coconut oil and whisk until melted. Remove from heat and whisk in sugar and sour cream until well combined. Set aside and allow to cool for at least 5 minutes.
In a separate bowl, whisk together eggs and milk. Add egg mixture to applesauce mixture and whisk until well combined. Stir in flour mixture and whisk for one minute.
Scrape batter into prepared pan and top with walnuts. Bake until a toothpick in the center comes out clean, between 40 and 45 minutes. Cool on a wire rack for 20 minutes. Remove bread from pan and allow to cool completely. (Gluten free bread is always best served the day it is made and warm. This bread will keep for up to 2 days wrapped at room temperature or frozen for up to one month.)