Preheat oven to 350 degrees.
Grease a 9x5 inch loaf pan with nonstick cooking spray.
In a bowl, use a hand mixer to beat the sugar and butter until crumbly.
Add the eggs, the bananas, vanilla and sour cream.
In another bowl, mix the flour, baking soda ,baking powder and salt.
Stir the dry mixture into the creamed mixture.
Fold in the chocolate chips and transfer to the loaf pan.
Bake 55-60 minutes or until baked through.
Cool 10-15 minutes before removing to a wire rack to cool.