For the Earl Grey-soaked prunes, place the prunes into a bowl and pour over the hot tea. Cover and set aside until the prunes have absorbed the liquid (about an hour).
For the pastry, sift the flour, icing sugar and salt into a large mixing bowl. Add the butter and rub it into the flour mixture using your fingertips, until the mixture resembles breadcrumbs. (Alternatively, blend to a crumb-like consistency in a food processor.)
Add the beaten egg yolks (reserving a little for glazing) and ground almonds and stir or mix with your hands until the mixture just comes together as a dough. Try not to overwork the dough. Wrap the dough in cling film and chill in the fridge for at least 30 minutes and up to one hour.
Preheat the oven to 160C/325F/Gas 3. Grease a 28cm/11in loose-bottomed tart tin with butter and dust with flour.
Roll the dough out on a lightly floured work surface to a thickness of approximately 2mm, taking care not to tear it. Carefully roll the pastry around the rolling pin and line the prepared tart tin with it, pressing the pastry lightly into the base and sides (leave any excess overhanging).
Line the pastry case with baking paper then fill with uncooked rice or baking beans. Bake the tart case in the oven for 10 minutes, then remove the baking paper and baking beans and brush the base with beaten egg yolk. Return the tart case to the oven to bake for a further 5-10 minutes, or until crisp and golden-brown. Set aside to cool, then trim away any overhanging pastry.
For the vanilla filling, heat the cream and vanilla pods or extract in a saucepan over a medium heat until just coming up to the boil. Whisk the eggs and sugar in a bowl until pale and fluffy.
Gradually pour the hot cream over the egg mixture, whisking well to combine, then return the mixture to the saucepan and cook over a low heat until it has thickened enough to coat the back of a spoon.
Pour the vanilla filling into the pastry case and bake in the oven for 20-25 minutes, or until the filling has set.
To serve, slice the tart and top each portion with the Earl Grey-soaked prunes.