Helado de Mantecado (Cuban Vanilla Ice Cream)

In a medium saucepan, combine the milk, cream, and ground cinnamon. Heat over medium heat until steaming but not boiling, then remove from heat and let steep for 10 minutes.

In a separate bowl, whisk the egg yolks with the sugar until pale and thick, about 2 minutes.

Slowly ladle about a cup of the warm milk into the yolks while whisking constantly to temper them. Then pour the yolk mixture back into the saucepan with the remaining milk.

Cook over low heat, stirring constantly with a wooden spoon, until the mixture thickens enough to coat the back of a spoon (about 170°F / 77°C on a thermometer). Do not let it boil.

Pour the custard through a fine-mesh strainer into a clean bowl. Stir in the vanilla extract, lemon zest, and a pinch of salt.

Cover the custard and refrigerate until completely cold, at least 4 hours or overnight.

Pour the chilled mixture into an ice cream maker and churn according to the manufacturer's instructions until soft-serve consistency, about 20 to 25 minutes.

Transfer the churned ice cream to an airtight container and freeze for at least 2 hours to firm up before serving.