Preheat the oven to 350F degrees.
Line a 9x5 inch loaf pan with parchment paper or grease and flour.
In a large bowl stir together the mashed bananas, melted butter and sugar.
Whisk in the eggs and vanilla extract. Then stir in the sour cream.
In a separate bowl whisk together the flour, baking soda, baking powder and salt.
Carefully fold the flour mixture into to banana mixture. Followed by ¾ cup chocolate chips.
Pour the batter into the prepared pan, and sprinkle the remaining ¼ cup chocolate chips on top.
Bake in the preheated oven for 50 to 70 minutes. If the top starts to brown too much, around 40 minutes through tent a piece of aluminium foil over top.
Allow to cool and then slice.