Place the milk and the cream into a large sauce pan and bring to blood temperature over a medium temperature
While it is heating, place the egg yolk and eggs into a mixing bowl and whisk to slacken
Add the fructose, custard powder, cornflour and vanilla and whisk to combine
Pour into the milk, stir to combine and lower the temperature
Whisk occasionally until it starts to thicken then stir continuously with a wooden spoon until it coats the back of the spoon
Pour into a jug and cover the top with cling film and set aside to cool
For the pâte brisée
Place the butter and fructose into a stand mixing bowl and cream together until pale
Add the egg and continue to beat until combined
With the speed set to slow, add the flour 2 tablespoons at a time and beat until the dough just comes together
Turn out onto a lightly floured surface and shape into a disc
Cover with cling film and place into the fridge for 30 minutes
Remove from the fridge and turn out onto a lightly floured surface
Leave to rest for 5 minutes before rolling out to 5mm thick
Place into a 23cm spring form tin and press the dough into the sides - do not worry if the dough breaks as you can patch work it together
Place the tin into the fridge for 30 minutes while you preheat the oven to 200° Celsius
Remove from the fridge and pour the cooled custard into the pastry
Trim the pastry to just above the custard ** and place the tin onto a baking tray
Place into the oven and bake for 25 minutes then reduce the temperature to 150° Celsius
Continue to bake for 30 minutes *** and then remove from the oven
Allow to cool completely before removing from the tin ****
Notes
* I used a combination of both, but you could use either one or the other, just double up on the weight** I did not do this which meant I had to trim it after baking which is what caused the crack*** I baked mine for 25 minutes and the centre was not quite set**** I have the worst spring form tin which does not allow for the removal of the base