For the custard:
2 tbsp flour
1 tsp cornstarch
a pinch of cinnamon
250ml whole milk
2 egg yolks
For the sugar syrup:
5 tsp Nutella
230g puff pastry
3 tbsp icing sugar
Preheat the oven to 220°C fan, leaving a baking tray in the oven to heat up.
Unroll the puff pastry and dust evenly with icing sugar. Roll the puff pastry back onto itself and cut into 10 slices.
Place the pastry slices cut-side down on the work surface and roll into discs big enough to line your muffin holes. Grease 10 holes of a muffin tin. Put a pastry disc onto each muffin hole, pricking the base with a fork. Put half a spoonful of Nutella at the bottom of each pastry. Refrigerate until needed.
Make the sugar syrup: Put the sugar and the water in a small saucepan and bring to the boil. Cook for approx. 5 minutes, swirling the pan from time to time, until you get a light brown caramel.
Meanwhile, melt the butter in a saucepan and add the flour, cornstarch and cinnamon. Slowly add the milk while stirring. Cook on a low heat for a few minutes until the mixture thickens.
As soon as the caramel has browned, pour the caramel into the hot milk mixture over a low heat and whisk well. Remove from the heat and leave to cool for 10 minutes.
Add the egg yolks to the custard while whisking vigorously. Pour the custard into a jug.
Take the muffin tins out of the fridge and pour the custard into the pastry cases, leaving a 1cm margin below the top as the custard will rise significantly in the oven.
Put the muffin tin on the hot baking tray in the oven and bake the pastries in the preheated oven for 12 minutes until the tops are quite dark.
Take the pasteis out of the tin and put on a wire rack to cool completely. Dust with a bit of cinnamon mixed with icing sugar before serving.
The pastéis are best eaten on the day they are made.