Preheat oven to 350 (180ºC)

Whisk together flour, sugar, baking powder, baking soda and salt.

Make a well in centre of flour mixture. In well, mix together butter, mashed bananas, eggs and vanilla. Stir to incorporate flour mixture- do not overmix! Dividing evenly, spoon batter into muffin cups.

Bake for 25 to 30 min