Step 1: Preheat the Oven and Prepare the Baking Dish
Preheat your oven to 350°F (175°C). Line an 8×8-inch baking dish with parchment paper, leaving an overhang for easy removal. Lightly spray with non-stick cooking spray to ensure the bars don’t stick to the sides.

Step 2: Cream the Butter and Sugar
In a large bowl, cream together ½ cup of room-temperature unsalted butter and 1 cup of packed brown sugar until the mixture is light and fluffy, about 2 minutes. You can use a stand mixer, hand mixer, or whisk if the butter is soft enough. Properly creamed butter and sugar create a lighter texture in the bars.

Step 3: Add Wet Ingredients
Add 1 large egg, 1½ teaspoons of vanilla extract, and ½ teaspoon of fine salt to the creamed mixture. Mix slowly on low to medium speed until just combined. Scrape the sides of the bowl to ensure everything is mixed evenly.

Step 4: Incorporate the Dry Ingredients
Add 1 cup of all-purpose flour to the wet ingredients. Stir on low speed or by hand, mixing just until the flour is incorporated. Be careful not to over-mix the batter, as this can result in dense bars.

Step 5: Add Mashed Bananas
Fold in 1 cup of mashed overripe bananas until fully combined. The bananas add moisture and sweetness, making the bars tender and flavorful.

Step 6: Fold in Chocolate Chips
Gently fold ¾ cup of chocolate chips into the batter. Reserve a few chips to sprinkle on top for a decorative touch. Folding ensures the chips are evenly distributed without overworking the batter.

Step 7: Pour and Bake
Spread the batter evenly into the prepared baking dish and sprinkle the reserved chocolate chips on top. Bake for 33-37 minutes, or until a toothpick inserted into the center comes out clean with a few moist crumbs. Rotate the pan halfway through for even baking.

Step 8: Cool and Cut
Let the bars cool completely in the pan on a wire rack. Once cooled, use the parchment paper overhang to lift the bars out of the pan. Cut into 16 squares using a warm, clean knife for sharp edges.