Preheat the oven to 350°F (175°C) and grease a loaf pan.
Prepare flax eggs by mixing flaxseed meal with water; let sit for 5 minutes to thicken.
Mash the bananas in a large bowl until smooth.
Stir in melted coconut oil, coconut sugar, flax eggs, and vanilla extract.
Whisk together flour, baking soda, salt, and cinnamon in a separate bowl.
Slowly add dry ingredients to wet ingredients, stirring until just combined.
For the mocha filling, heat coconut milk in a small saucepan over low heat.
Remove from heat and stir in chocolate chips, espresso powder, cocoa, and vanilla.
Mix until smooth and glossy. Try not to eat it all.
Pour half of the banana batter into the loaf pan.
Spread the mocha filling evenly over the batter.
Top with the remaining banana mixture and swirl with a knife.
Bake for 50-55 minutes, or until a toothpick inserted in the center comes out clean.
Cool for 15 minutes before slicing—if you can wait that long.