Preheat oven to 350 degrees; line a muffin pan with muffin liners, set aside
In a medium sized bowl whisk together flour, sugar, cocoa powder, baking soda and salt. Set aside.
Now in a large bowl mash bananas with a potato masher or fork until uniformly smooth.
Add in butter, eggs and vanilla. Mix well.
Next, add the flour mixture to the wet ingredients and mix until just combined.
Fold in your chocolate chips to the muffin batter until evenly distributed.
Fill your prepared muffin tin with batter almost to the top, you should end up with ~12 muffins.
Bake your muffins for ~27 minutes or until a toothpick comes out clean.
Allow your muffins to cool and enjoy!