
Preheat the oven to 350 degrees F. Line a 12 cup muffin tin with liners and spray with nonstick cooking spray.
In a large bowl, mix together banana, brown sugar, eggs, almond milk, and vanilla extract.
In a separate bowl, whisk together flour, baking powder, baking soda, cinnamon, and salt.
Add dry ingredients to wet ingredients and mix until just combined. Stir in melted coconut oil.
Add half of the batter to another bowl. Stir cocoa powder and chocolate chips into this batter.
Spoon regular banana batter and chocolate batter alternately in the muffin liners.
Swirl batters gently with a knife.
Gently shake the muffin pan to even out the batter and top with chocolate chips.
Bake for 18-25 minutes until a tester comes out clean. Cool and sprinkle with sea salt before serving.