In a saucepan, combine the flour and milk, then heat over medium heat until the mixture thickens.
Stir in the vanilla bean paste and egg yolks, mixing well.
In a separate pan, combine the sugar, water, and cinnamon stick, bringing it to a boil.
Gradually pour the hot sugar mixture into the egg mixture while whisking continuously.
Take the sheet of puff pastry, fold it in half, then roll it up and cut it into 12 equal pieces.
Place each piece into the holes of a muffin tin, using wet fingers to press the pastry up the sides.
Pour the custard mixture into each pastry shell.
Bake in the oven at the highest temperature until the tops are blackened in spots and the pastry is crispy.
Once done, sprinkle with icing sugar and serve.
