Preheat oven to 350 degrees. Grease and line a loaf pan with parchment paper.
In a medium bowl, mix melted butter, sugar, eggs, mashed bananas, vanilla, and sour cream or yogurt.
In a large bowl, mix flour, baking powder, baking soda, and salt.
Mix wet ingredients into dry ingredients with a rubber spatula. Be careful not to overmix.
Fold in chocolate chips.
Pour into the loaf pan and bake at 350 degrees for about an hour. Check banana bread at around 45 minutes and then again, every 5 minutes until a toothpick comes out clean.
Let bread cool in the pan for at least 30 minutes before removing. Serve immediately or package in an airtight container. Add my grandma's famous chocolate frosting to turn your bread into an even sweeter treat!