Method

1. Mix the icing sugar, glucose, condensed milk, flavouring and butter with an electric mixer in a bowl until smooth and light, then beat in the baking margarine until smooth.

2. In a jug, stir the icing sugar into the cream until dissolved, then add any colouring or flavouring you want, or just leave it plain. Beat this gradually into the butter mixture until light and fluffy.

3. This buttercream keeps very well covered at room temperature for 2-3 days and can be warmed slightly and re-beaten if the texture is too firm.