Preheat Oven:

• Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang for easy removal. Set aside.

Melt Butter and Chocolate:

• In a microwave-safe bowl, combine the unsalted butter and chopped dark chocolate. Microwave in 20-second intervals, stirring after each, until the mixture is smooth and fully melted.

Mix Wet Ingredients:

• In a large mixing bowl, whisk together the granulated sugar and eggs until well combined.
• Add the vanilla extract and mashed bananas to the mixture, stirring until fully incorporated.

Combine Wet and Dry Ingredients:

• Pour the melted butter and chocolate mixture into the wet ingredients, stirring until smooth.
• Sift in the all-purpose flour, unsweetened cocoa powder, and salt. Gently fold the dry ingredients into the wet mixture until just combined, being careful not to overmix.

Bake:

• Pour the batter into the prepared baking pan, spreading it evenly.
• Bake for 35-40 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.

Cool and Serve:

• Remove the brownies from the oven and allow them to cool completely in the pan.
• Once cooled, lift the brownies out of the pan using the parchment paper overhang. Cut into squares and serve.