Spray two 12-cup miniature muffin tins with vegetable cooking spray.
Mix banana, yogurt, and vanillain a small bowl.
Mix flour, baking powder, baking soda, and salt in a medium bowl.
Beat butter and sugar in a large bowl with an electric mixer at medium-high speed until light an fluffy. Add egg and beat until smooth.
Reduce speed to low and beat in one third of the dry ingredients, then half the yogurt mixture. Add another on third of the dry ingredients, then remaining yogurt, and remaining dry ingredients, beating until batter is just smooth. Increase speed to medium-high and beat until batter light and fluffy, about 30 seconds.
Stir in chips.
Completely fill each muffin cup with batter. Stud tops of muffins with extra chips, if you like.
Bake on oven rack adjusted to middle of oven until golden brown, 12-14 minutes.
Set pans on a wire rack to cool slightly. Remove muffins from tins and invert on rack to cool.