Individual servings of tiramisu trifle, this is great for a dinner party dessert.
To make the custard, In medium saucepan over medium heat, heat milk until bubbles form at edges.
In a bowl, combine sugar, cornstarch and salt. Pour into hot milk, a little at a time, stirring to dissolve.
Continue to cook and stir until mixture thickens enough to coat the back of a metal spoon.
Remove from heat, stir in vanilla and butter.Chill until cold.
Mix the coffee and liqueur in a wide dish.
In another bowl mix the marscarpone with the custard until smooth using an electric hand mixer.
Take about a third of the sponge fingers and dip them in the coffee/liqueur mix and line the bottom of 8 serving dishes with them, drizzle a bit more of the liquid over the sponge fingers.
Top with custard then more sponge cake.
Chill for at least 2 hours or up to a day.
Just before serving top with whipped cream and sprinkle chocolate.