Banana Chocolate Chip Muffins

Our friends were babysitting our kids so I wanted to bring them a treat. I had two very ripe bananas to use up and decided to try my hand at muffins. I wanted something fairly healthy and not filled with butter. I adapted the recipe I found by using vanilla yogurt and adding semi sweet chocolate chips. I really wanted to add walnuts but I didn't have any. These muffins were delicious - they had