Petits Fours Icing

In a saucepan, stir together the caster sugar, cream of tartar and water. Bring to the boil over medium-high heat, and cook without stirring until the temperature is between 106 to 112 degrees C, or until a small amount of syrup dripped from a spoon can spin a long thread.

When the syrup comes to the proper temperature, remove from heat, and stir in icing sugar about 50g at a time until the icing is thick enough to coat a metal spoon. Test by pouring over a small piece of cake. Adjust the amount of icing sugar as needed to get a good pouring consistency. Use while warm, or reheat over simmering water. Keep covered with cling film when not in use to prevent a crust from forming on the top.