Place the sugar and the butter in a bowl of an electric mixer fitted with a paddle attachment. Beat on medium-high until combined but not creamed.
Add the egg and the vanilla extract, and mix again until combined.
Add the flour at once and mix until combined, do not over-mix. Cover the dough in clingfilm and allow to rest in the fridge for one hour.
Preheat the oven to 180°C
Once chilled, roll out the pastry on a floured surface to the thickness of about 5mm. Brush a 22cm pastry tin with melted butter and line the tin with the pastry dough.
Line the douth with baking paper and fill the paper with baking beans or rice, bake the tart shell in a preheated oven for about 15 minutes or until lightly golden.
Remove from the oven, and remove the paper and the baking beans and set it aside to cool.
Milktart Custard
Add the condensed milk, milk and cinnaon stick to a medium pan set over medium heat. Heat until almost boiling.
Meanwhile, add the egg yolks and the cornflour to the bowl of an electric mixer fitted with a whisk attachment. Beat until combined.
In a steady stream add the hot milk mixture to the egg mixture while whisking, do this slowly to temper the eggs. Continue until all of the milk has been added. Transfer the mixture to a clean pot over medium heat.
Whisk continuously until the custard thickens, once thick remove from the heat and whisk in the butter.
Pour the custard into the baked tart shell and place the tart into a preheated oven set at 150°C bake for 20 minutes. Remove from the oven and dust with cinnamon.
Allow the milktart to cool to room temperature and then place it in the fridge for 4 hours or ideally overnight. Enjoy!