1.Preheat oven to 180°C/350°F. Line a 12-hole (1/3-cup/80ml) muffin pan with paper cases.
2.Thickly slice banana; combine with juice in a medium bowl.
3.Sift flour and sugar into a large bowl; stir in Weet-Bix and mashed banana. Add buttermilk, butter and egg; stir until mixture is just combined. Spoon mixture into paper cases; top with banana slices.
4.Bake muffins for about 25 minutes. Stand muffins in pan 5 minutes before turning, top-side up, onto a wire rack to cool.
5.Make honey icing; stir honey and milk in a small saucepan over low heat until combined. Remove from heat; gradually stir in sifted icing sugar.
6.Spoon icing over cold muffins; stand until set.
You will need 2 large (460g) overripe bananas to make 1 cup mashed banana.