This sauce goes well with decadant chocolate desserts such as chocolate and pistachio bavarois where a sweet fresh sauce is needed to cut through an intense richness. Made with eggs, it is like a thin custard. The spike of Marsala intensifies the orange flavour and aroma. If you don't have Marsala, dry sherry can be used instead.
Put eggs, sugar, orange zest and orange juice into a blender or food processor and process for a few seconds.
Transfer toa non-stick saucepan and cook over a low heat until mixture thickens. Keep stirring to prevent sticking but do not allow the mixture to boil as it will separate.
Once thickened, quickly beat in the margarine and marsala.
Transfer to a bowl or jug and allow to cool, then cover and chill until required to serve.