Put butter in saucepan on 'low' to melt. While it melts, use a pastry brush to lightly grease the top of the muffin tin using a little bit of the melted butter. Put greaseproof paper cups in 7 large muffin tin holes.
Sift flour, baking powder & baking soda into a large bowl.
Stir in castor sugar, egg, banana, vanilla essence & butter. After a few stirs, add chocolate chips and stir.
Fill each muffin hole paper cup (to top of paper cup) with spoonfuls of mixture.
Before putting in oven, lightly drop muffin tin on bench. Fan bake for about 25 minutes or until golden brown. (Turn muffin tray around in oven after about 12 minutes - especially if you are baking in an old oven).
When cooked, bring out of oven and leave muffins in muffin tin for 5 minutes. Turn out upside down onto cooling rack and allow to cool for another 5 minutes.
Variation on recipe:
Kiwifruit muffins – omit bananas & choc chips – replace with 2 cups kiwifruit.
Feijoa & Banana muffins – omit choc chips – add 1 cup feijoa.
Feijoa muffins – omit bananas & choc chips – replace with 2 cups feijoa
(Feijoa is also known as Pineapple Guava)