Place the butter in a bowl, whisk in the sugar and salt. Add the eggs one at a time and continue to whisk until the mixture becomes lighter in colour. Mash the bananas with the lemon juice and stir in. Mix in the flour, baking powder and muesli along with the milk, transfer to the prepared tin.
Spread the muesli on top of the cake mixture, top with knobs of butter, sprinkle with sugar.
Approx. 40 mins. in the centre of an oven preheated to 180°C. Remove from the oven, leave to cool on a rack, dust with icing sugar.