Preheat oven to 360°F (180°C) and arrange the baking rack onto the middle shelf.
In a large bowl, whisk together the bananas, coconut oil, almond milk, maple syrup and vanilla.
In another bowl, mix together the chickpea flour with the whole wheat flour, baking powder, cinnamon, nutmeg and sea salt.
Slowly incorporate the dry ingredients into the wet ones and mix until just combined. Add in the walnuts and chocolate chips and gently stir until combined.
Transfer the mixture into a 10-inch x 5-inch (25-cm x 13-cm) loaf tin covered with parchment paper, then level the batter surface with a spoon. Bake in the oven for 40 to 45 minutes, or until the loaf is golden on top. Check for doneness by inserting a toothpick into the center. If it comes out clean, the banana bread is ready.
Remove from the oven, allow to cool completely, then transfer the banana bread onto a serving plate and serve.