Preheat oven to 350 degrees F (175 degrees C). Grease or line muffin pan with paper liners.
In a large bowl, cream together butter and brown sugar. Beat in eggs, one at a time, then stir in vanilla. Beat in mashed bananas until smooth. Combine flour, baking soda and salt; stir into the banana mixture just until moistened. Fold in chocolate chips.
Fill greased or paper-lined muffin cups two-thirds full. Bake in preheated oven for 20 to 25 minutes, or until a toothpick inserted into center of a muffin comes out clean.
Interesting Facts
Muffins are a great way to use up overripe bananas.
You can substitute other types of chips in place of chocolate chips, such as white chocolate or butterscotch.
This recipe can also be used to make a delicious banana bread.