To make the pastry, add the flour, icing sugar and butter to the bowl of a food processor or mixing bowl and rub in the butter until the mixture resembles fine crumbs. Add the egg yolks and vanilla and mix to a soft ball.
Preheat the oven to 190°C/Fan 170°C/Gas 5. Roll out the pastry on a lightly floured surface and stamp out 9.5cm circles with a plain or fluted biscuit cutter and press into sections of 12 hole buttered muffin tin. Re-roll the trimmings and continue until all sections of the muffin tin are lined. Prick the bases of the tarts with a fork and chill for 30 minutes.
Line each tart case with a square of non-stick baking paper and line with baking beans then bake blind for 8 minutes, remove the paper and beans and bake for 3-4 minutes until bases are crisp and the top edges pale golden.
Reduce oven temp to 170°C/Fan 150°C/Gas 3. To make the filling lightly whisk the eggs, egg yolks, icing sugar and vanilla together, then add the cream and whisk briefly until smooth.
Strain the custard through a sieve into a jug. Pour into the baked tart cases then add 3 raspberries to each. Bake for 15-20 minutes until the custard is just set then leave to cool in the tins. To serve, loosen the tarts with a knife then remove from the tin, serve as they are or lightly dusted with sifted icing sugar.