Extra Moist Banana Bread

butter, softened1 cup white sugar2 eggs1 teaspoon vanilla extract1 teaspoon lemon juice1½ cups all-purpose flour1 teaspoon baking powder1 teaspoon baking soda½ teaspoon salt½ cup sour cream½ cup pecan pieces1 cup mashed bananas (2 - 3 very ripe bananas)