1 Preheat oven to 375℉ (190℃). Lightly grease 10 muffin cups, or line with cupcake liners. 

2 In a large bowl, mix together 1½ cups flour, baking soda, baking powder and salt. In another bowl, beat together bananas, sugar, egg, oil and vanilla. Stir the banana mixture into the flour mixture just until moistened. Add in chocolate chips and mix. Spoon batter into prepared muffin cups. 

3 Bake in preheated oven for 18 to 20 minutes, until a toothpick inserted into center of a muffin comes out clean.