Preheat your oven to 350°F (175°C) and grease the baking pan or line it with baking parchment paper for easy removal.
In a mixing bowl, mash the ripe bananas thoroughly until smooth. You can use a fork or a potato masher.
Add the melted butter to the mashed bananas and mix well.
Stir in the granulated sugar, followed by the eggs and vanilla extract. Mix until fully combined.
In a separate bowl, sift together the flour, cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the banana mixture, stirring until just combined. Be careful not to overmix.
If desired, fold in chocolate chips for added fudginess.
Pour the brownie batter into the prepared baking pan and spread it evenly.
Bake in the preheated oven for 25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs attached.
Allow the brownies to cool in the pan for about 10 minutes before transferring them to a wire rack to cool completely.
Once cooled, slice into 12 equal squares and enjoy!