Soak prunes in 500ml hot Earl Grey tea for one hour until liquid is absorbed.
Sift flour, icing sugar, and salt into a bowl and rub in 75g butter until it resembles breadcrumbs.
Mix in 2 beaten egg yolks and ground almonds to form a dough, then chill for 30-60 minutes.
Preheat oven to 160°C and grease a 28cm tart tin with butter and flour.
Roll dough to 2mm thickness and line the prepared tin, leaving excess overhanging.
Blind bake with baking beans for 10 minutes, remove beans, brush with egg, and bake 10 more minutes.
Heat cream and vanilla in a saucepan until nearly boiling while whisking 12 yolks and caster sugar.
Combine cream and egg mixtures and cook over low heat until thickened enough to coat a spoon.
Pour filling into the case and bake for 20-25 minutes until set.
Slice the tart and serve topped with the soaked prunes.