In a nonreactive stockpot, combine the milk, sugar and cinnamon. Bring to a simmer and reduce by a third (about 25 to 30 minutes).
Meanwhile, fill a saucepan halfway with water and bring to a simmer over medium heat.
Whisk the egg yolks in a stainless steel mixing bowl, then slowly pour the hot reduced milk mixture into the yolks, whisking constantly. Set the bowl atop the pan of simmering water.
Using a wooden spoon, stir the mixture constantly until it coats the back of the spoon.
Immediately remove the bowl from the stove and place it on top of an equally sized bowl filled with ice. Whisk gently to cool as quickly as possible.
Once cool, whisk in the rum and vanilla. Strain through a fine-mesh strainer into a half-gallon jar. Garnish with freshly grated cinnamon.
¾ cup granulated sugar
1 cinnamon stick
6 egg yolks
¼ cup light or golden rum
1¼ tsp. vanilla extract
This article appears in Dec 1-31, 2010.