Grease a 14cm x 24cm loaf pan. Line base and two long sides with baking paper.
Beat butter and sugar in a small bowl with an electric mixer until light and fluffy. Add eggs, one at a time, beating until combined. Stir in bananas and vanilla essence.
Combine milk and bicarbonate of soda in a small jug. Fold flour and milk mixture into banana mixture. Spoon into prepared pan.
Cook in a moderate oven, 180c, for 40 minutes, or until cake is cooked. Stand in pan for 5 minutes before turning onto a wire rack to cool.
To make the lemon icing, beat cream cheese in a small bowl with an electric mixer until lightly and fluffy. Gradually beat in icing sugar mixture and rind until combined.
Spread lemon icing over cake. Decorate with shredded orange rind and banana slices.