Line a 12-section bun tray with paper cake cases. Sift the flour, baking powder and bicarbonate of soda into a bowl.
Mix together the melted butter, muscovado sugar, eggs and mashed bananas in a separate bowl. Tip in the dry ingredients and mix together gently until evenly combined. Divide the cake mixture between the paper cases.
Bake in a preheated oven, 160°C (325°F), Gas Mark 3, for 25 minutes or until risen and just firm to the touch. Transfer to a wire rack to cool.
Beat together the butter, honey and icing sugar in a bowl until smooth and creamy. Spread over the tops of the cakes using a small palette knife. Decorate with dried banana slices, if liked.