Rub flour, butter, and sugar together until the mixture resembles breadcrumbs.
Mix in the egg yolk until a dough starts to form, adding egg white if too dry.
Flatten the dough to 2cm thick, wrap in film, and refrigerate for 30 minutes.
Grease a 25cm tart tin and chill it in the fridge.
Roll out the pastry between cling film to 3mm thickness.
Line the chilled tin with pastry, trim the edges, prick with a fork, and chill.
Preheat the oven to 180°C.
Blind bake the pastry with parchment and beans for 15-20 minutes.
Remove beans, brush with egg white, and bake for 5-8 minutes to seal.
Whisk egg yolks and caster sugar, then stir in flour and salt.
Boil milk with a scored vanilla pod and infuse for 10 minutes.
Slowly whisk hot milk into the egg mixture and return to the pan.
Whisk constantly over low heat until thickened, then pour into a cold bowl.
Whisk double cream with vanilla extract and sugar until soft peaks form.
Fold the whipped cream into the cooled pastry cream and chill.
Fill the pastry case with pastry cream and top with raspberries.
Glaze the fruit with a mixture of redcurrant jelly and hot water.
Remove the tart from the tin and serve on a plate.