A super sweet, easy treat!
Turn the oven up to 350 F. While that's heating up, grease a 9×13 baking pan.
In a big bowl, use a whisk or electric mixer to beat together the butter, sugar and eggs. Add in the banana, buttermilk and vanilla and mix well.
Stir the flour, baking powder, baking soda and salt into the mixture, then fold in 1 ¼ cups of the chocolate chips.
Pour your batter into the prepped pan and sprinkle the rest of the chocolate over it.
Bake the pan for 30 minutes until you can stick a toothpick in and pull it out clean.
Let the pan cool off completely, then cut it up into small squares.