Preheat oven to 180℃ (350°F). Grease an 18cm (7”) springform pan.
I a medium bowl, mash the banana well, whisk in the egg, then add the maple syrup.
Add coconut milk, oil, and vanilla extract, and whisk until combined. If your coconut milk has a topping of coconut cream, give it a stir before adding it to the bowl.
In a large bowl, sift together the flour, cocoa powder, baking powder, and salt and then stir in the coconut.
Add the dry ingredients to the wet, and using a whisk, gently mix everything together. Don't overmix.
Using a spatula, scrape the sides of the bowl, then pour into the prepared pan. Please note: the batter is very runny, so don't panic.
Bake for 30-35 minutes. The cake is ready when an inserted skewer comes out clean. Leave the cake to cool for around 10 minutes, then remove the outside part of the springform, and turn out onto a wire rack. Allow to cool completely.