Boil the sugar and water together until they reach 112C or, if you dont have a candy thermometer, a small drop of the syrup forms a soft ball in ice water

Remove from heat

Break up the marshmallows, if you are using large ones, and add them to the syrup, dont stir

Leave to melt for a few minutes

While waiting for the marshmallows to melt, beat the egg white until stiff peaks form

Add the syrup and marshmallows to the egg white and beat well until it is all combined to a spreadable consistency

Mine was runny but if yours is not spreadable add a few drops of water at a time until its right

Spread over your cake or cupcakes