01 -
Preheat the oven to 350°F (177°C). Line an 8x8 (20 cm) pan with parchment paper covering the bottom and two sides.
02 -
Place the butter in a microwave-safe bowl and heat for 1 minute. Stir and, if needed, heat for an additional 15 seconds. Allow the melted butter to cool for 10-15 minutes until warm but not hot.
03 -
In a mixing bowl, whisk together the flour, baking powder, and salt until well combined.
04 -
In a large bowl, whisk the cooled butter with the light brown sugar until well mixed. Add the egg, mashed bananas, and vanilla extract, and whisk until smooth. The mixture may appear slightly curdled—this is normal.
05 -
Gradually stir the dry ingredients into the wet ingredients, mixing until just combined. Fold in ½ cup of the mini chocolate chips, reserving the remainder for topping.
06 -
Pour the batter into the prepared pan and use a spatula to spread it evenly. Sprinkle the remaining chocolate chips on top. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean or with a few crumbs.
07 -
Allow the bars to cool to room temperature in the pan. Use the parchment paper to lift the bars from the pan, slice into squares, and serve.