Preheat oven to 200C or 180C fan-forced. Grease muffin tray using butter and pastry brush or line with paper cases.
Melt butter in a heatproof bowl in the microwave. Set aside to cool slightly.
Sift flour into mixing bowl. Stir in sugar. Make a well in the centre of dry ingredients.
Using a whisk, lightly beat milk, eggs and butter in a jug. Add to dry ingredients, a few stirs then add mashed banana. Using a mixing spoon, gently combine ingredients.
Stir in choc bits, coconut and maple syrup. Don't beat the mixture or the muffins will be tough.
Spoon the mixture evenly into the muffin tray. Bake for 20 minutes or until firm on top when lightly touched. Leave in the tray for a few minutes.
Transfer the muffins to a rack to cool.