For the pastry, use a food processor (or mixing bowl and wooden spoon, if you’re feeling energetic) to cream the butter and sugar together. Pulse in flour, eggs, vanilla seeds or orange zest and a pinch of salt, and add little splashes of milk until it forms a ball. Wrap in clingfilm and chill for an hour.
Roll out pastry on a floured surface to line a greased, loose-bottomed 27cm-diameter, 2.5cm-deep tart tin. Push pastry into the sides, prick with a fork, line with 4 pieces of clingfilm, then fill with rice or dried beans. Chill tart case for 1–2 hours.
Meanwhile, preheat oven to 180C/gas 4. Bake the tart case (clingfilm and rice in place) for 10 minutes, then remove clingfilm and rice and cook for another 5 minutes. Remove and turn oven down to 170C/gas 3.
Melt chocolate in a bowl over a pan of simmering water. Heat the milk and cream in a pan with cardamom, then remove from heat and infuse for 10 minutes. Beat the sugar and egg yolk with a pinch of salt, then stir into chocolate. Stirring all the while, add milk by straining it through a sieve, discarding cardamom pods. Pour chocolate mixture into the tart case and scatter over the raspberries. Bake for about 25 minutes – the tart should still be wobbly in the middle. Remove from oven, let cool, then chill in the fridge before dusting with icing sugar and serving with crème fraîche, or simply with more berries.