To make the custard cream, heat the milk and vanilla in a medium saucepan until just before boiling point (this is called scalding).
In the meanwhile, mix together the egg yolks, sugar, flours and pinch of salt until the mixture is smooth and thick.
When the milk mixture is hot, pour it slowly into the egg yolk mixture whilst continuously mixing.
When all the milk has been incorporated, transfer the runny mixture back to the saucepan and over a gentle heat, allow to cook and thicken, whisking continuously.
When the mixture is thick and there is no flouriness when you taste it, remove from the heat and beat in the mascarpone cheese.
Place in a bowl and put a piece of cling film directly onto the surface of the cream to prevent a skin from forming. Place in the fridge and allow to cool.
To prepare the strawberries, combine the sliced strawberries with the caster sugar and vanilla and stir well. Allow to stand for 20 minutes until the strawberries have released a lot of juice.
To assemble the trifles, layer the sliced madeira cake with the macerated strawberries and the custard cream.
Top with whipped cream, sliced strawberries and a sprinkle of icing sugar.