Prepare the Pan Line an 8x8-inch baking dish with parchment paper, allowing the edges to hang over the sides for easy removal.
Melt the Chocolate In a microwave-safe bowl, melt the chocolate chips and butter in 30-second intervals, stirring in between until smooth and fully melted.
Combine Ingredients In a mixing bowl, add the mashed bananas, sweetened condensed milk, vanilla extract, and a pinch of salt. Mix until well combined.
Blend in the Chocolate Pour the melted chocolate mixture into the banana mixture and stir until fully incorporated.
Pour and Set Pour the fudge mixture into the prepared pan, spreading it evenly. Sprinkle any desired toppings over the top.
Chill Place the pan in the refrigerator for at least 2-3 hours or until the fudge is set. For quicker setting, you can freeze it for about an hour.
Serve Remove the fudge from the pan using the parchment paper overhang, slice into squares, and serve chilled.
