Preheat the oven to 350°F (180°C). Line a 12-hole muffin tray with paper cups, or grease your tray with coconut oil. Set aside.
Peel the ripe bananas, mash on a plate with a fork or potato mashed until smooth. It is ok if you still have chunks of banana. Measure precisely the amount required by the recipe and place it in a large mixing bowl.
In the large mixing bowl, combine mashed banana, almond milk, melted coconut oil, and vanilla.
Stir in cocoa powder, coconut sugar, salt, baking powder, and baking soda until smooth and well combined. Now add the all-purpose flour in two equal batches. Stir between each batch until smooth and completely incorporated. You want a smooth batter with no flour lumps - it is ok to have banana lumps!
Stir in 1/2 cup dark chocolate chips in the batter if desired.
Transfer the batter evenly into the 12 muffin holes.
Bake for 25-35 minutes or until set on top and a skewer inserted in the center of the muffin comes out clean
Cool on a rack for 1 hour before serving. Note that the muffin paper cups can stick to the batter if your muffins are still hot. They always peel off better the next day.
Store in the fridge for 7 days, in an airtight container or cake box.
Freeze in an airtight box and thaw at room temperature the day before.
Flour: this recipe doesn't work with almond flour, coconut flour, or oat flour. You must use all-purpose flour or spelt flour.