Preheat oven to 350F.
Grease and line with parchment paper a regular sized loaf pan(approx. 9x5).
In a large bowl add the mashed bananas, coconut oil, coconut sugar, eggs and milk. Stir until well combined.
In a separate bowl sift together the flour, cocoa, baking soda and salt. Pour the dry ingredients into the wet ingredients, add the chopped dark chocolate and gently stir until the dry flour is no longer visible.
Pour the batter into the prepared loaf pan.
Sprinkle the remaining 1 tbsp of coconut sugar on top of batter.
Bake for about 55 to 65 minutes or until a toothpick inserted into the center comes out clean.
Let cool in the pan for about 5 minutes. Transfer to a cooling rack, let cool and enjoy.