Preheat the oven to 350 degrees F. Lightly brush the inside of a 10-by-5-inch loaf pan with coconut oil and line with a strip of parchment paper. Set aside.
In a large bowl, mash the bananas with the back of a fork until only a few lumps remain. Add the egg and mix until smooth. Using the fork, whisk in the almond milk, sugar, almond butter, coconut oil, vanilla and salt until smooth and incorporated. Add the almond flour, rice flour, baking soda and cinnamon and stir until combined with a rubber spatula. Stir in the chocolate chips.
Pour the batter into the prepared loaf pan and sprinkle the walnuts on top. Bake until the bread is firm to the touch and a toothpick inserted in the center comes out with very few crumbs, 1 hour 5 minutes to 1 hour 10 minutes. Allow to cool for 30 minutes in the pan resting on its side. Loosen the edges with a knife and remove to a wire rack to cool completely. The bread will keep for 4 days at room temperature or can be sliced and frozen for up to 1 month.
This bread gets quite dark when baking, but do not fret. It is not burned but simply a lovely nutty flavor.