Heat the milk, cinnamon stick, and sugar in a saucepan. Just before it starts to boil, lower the heat.

Separate the egg yolks from the whites. Save the whites for making omelets or meringue. Beat the yolks with the cornstarch. Once combined, add the mixture to the saucepan with the milk, stirring constantly with a whisk to prevent lumps. When the mixture thickens, remove from heat and use a ladle to fill clay ramekins.

Refrigerate for a couple of hours. Before serving, sprinkle sugar on top and caramelize it with a kitchen torch or electric burner. You can also serve it with a rolled wafer cookie, a touch I saw at the Tres Turons restaurant in Arenys de Munt.