Put caster sugar, yolks, vanilla and butter in processer and whiz until smooth (30 seconds)
Tip in flour and salt, pulse until mix binds in large clumps.
Tip pastry onto work surface and shape into a ball. Do not need. Wrap in plastic and chill for 30 minutes until firm.
Roll dough between plastic wrap to a wide enough circle to fit 23cm loose bottomed tart tin.
Line tin, press pastry into flutes and trim excess. Chill shell for 15 minutes.
Line pastry shell with greaseproof paper and fill with baking beans and bake on hot baking sheet for 15 minutes.
Remove paper and beans and put back in oven for about 5 minutes until firm and dry.
Lower oven temp to 180°.
Filling
Mix eggs with sugar, cornflour and cinnamon until just mixed. Try to avoid a froth forming. Stir in teh wine and pour filling into the pastry shell and bake for 20-30minutes until set.
Cool in tin for 5 minutes, remove and cool completely.
Dust with icing sugar and serve with crème fraiche.