For the pastry:
1 Preheat the oven to 210 degrees or 190 if using a fan oven. Line a 20x20cm square baking tin with parchment paper.

2 Cut the pastry into a square a few centimetres larger than the tin and line the tin, pressing the pastry up the sides. Prick the base of the tin with a fork, then freeze for at least 15 minutes.

3 Line the pastry with parchment paper and fill with baking beans or uncooked rice and bake for 20 minutes. Remove the parchment paper and continue cooking for a further 10 minutes.

4 Brush the base and sides of the pastry with the egg yolk and return to the oven for a further two minutes to seal the pastry; this will avoid a soggy base. Remove from the oven and allow to cool while making the filling.

For the custard:
1 Increase the oven temperature to 240 degrees or 220 fan. Make a syrup by placing the water, sugar, orange zest, cinnamon sticks and vanilla into a small saucepan over a medium heat. If using a vanilla pod, put the seeds and pod into the pan, if using the extract, add it straight to the pan. Bring the syrup to a simmer to dissolve the sugar, then remove from the heat and set aside to cool and infuse.

2 Put the cream and milk into another saucepan and gently bring to a simmer. In a bowl, whisk the whole egg, egg yolks and cornflour together until pale.

3 Pour the hot cream over the egg mix, whisking all the time, then pour back to the saucepan and place back on a low heat.

4 Remove the orange zest, cinnamon and vanilla (pod) from the syrup and pour the syrup into the custard. Cook the custard until it starts to boil, then remove from the heat.

5 Spread the custard on top of the cooked pastry base, and place in the oven for 20 minutes, until set and the top has blistered.

6 Remove from the oven leave to cool completely in the tin.  

For the topping:
1 Mix the sugar and cinnamon together and sprinkle on top of the tart.

2 Cut into squares to serve.