Servings: 3cups, serving 6 adequately
- Concentrate the milk. In a 4-quart saucepan, stir together the milk, sugar and cinnamon stick. Bring to a boil over medium heat and cook, stirring regularly, until the quantity has reduced to 2 ¾ cups, 20 to 30 minutes.
- Cook the rompope. Whisk together the egg yolks in a stainless steel bowl or top of a double boiler. Slowly pour our the hot milk mixture into the yolks, whisking nearly constantly. Set the bowl or top of double boiler over—not in—gently simmering water. Stir nearly constantly, until the mixture thickens enough to coat the back of a wooden spoon somewhat thickly, about 15 minutes. (The most secure way to judge doneness: the rompope will reach 175 degrees on a thermometer—don’t let it go higher.) Let cool (I like to do this quickly by nestling the bowl or double boiler top into an ice bath and stirring frequently). Whisk in the vanilla and booze.
3. Storing. Strain the mixture into a jar or bottle. Refrigerate until cold—the flavors are better if you refrigerate the rompope for a day or so before serving.