Place 1 tablespoon cornflour, 2 tablespoons caster sugar and 3egg yolks in a bowl and whisk until smooth, then whisk in one whole egg.
Heat 500ml (18floz) milk until almost boiling then gradually pour onto the egg mixture while whisking well.
Place the bowl over a pan of gently simmering hot water and keep whisking until the custard thickens enough to coat the back of a spoon. Remove from the heat and whisk in 1 teaspoon vanilla extract. Cover with a sheet of dampened parchment, and allow to cool.
To make the trifle
Spread 8 boudoir biscuits in the bottom of a serving bowl and sprinkle with 3 tablespoons marsala wine, sherry or dessert wine. Pile 300g (11oz) raspberries on top.
Break 75g (3oz) ratafia biscuits into pieces and scatter over the raspberries. When the custard is cool spoon over the raspberries and biscuits and level the top. Chill.
To make the syllabub
Place 600ml (1pt) cream, 4 tablespoons sugar, 150ml (¼pt) marsala, sherry or dessert wine. in a mixing bowl and add the grated zest. and juice of 1 lemon. Whisk until it is just holding its shape. Carefully spoon over the custard.
Just before serving arrange a few extra raspberries on top and sprinkle with nuts or dragees
Notes
Nutrition information is calculated usingan online nutrition database - is approximate and is meant as a guideline only. Not suitable for freezing.