01 -
Preheat oven to 350°F (175°C). Grease a 9x13-inch baking pan with nonstick spray and set aside.
02 -
In a large bowl, using a whisk or hand mixer, beat the melted butter, granulated sugar, and eggs until well combined.
03 -
Incorporate the mashed bananas, buttermilk, and vanilla extract into the wet mixture and mix until smooth.
04 -
Stir in the flour, baking powder, baking soda, and salt until just combined. Avoid overmixing.
05 -
Gently fold in 1¼ cups of mini chocolate chips, reserving the remainder for topping.
06 -
Pour the batter into the prepared pan and sprinkle the remaining chocolate chips evenly over the top. Bake for 30 minutes, or until a toothpick inserted in the center comes out clean.
07 -
Allow the bars to cool completely in the pan before slicing into squares and serving.