Combine in a medium saucepan and bring to a simmer over medium heat, stirring to dissolve the sugar:
Beat together in a medium heatproof bowl:
Slowly stir about ½ cup of the hot milk mixture into the beaten egg yolks. Stir the egg mixture back into the milk. Cook over medium-low heat, stirring constantly, until the custard reaches 175°F and coats the back of a spoon. Do not allow the mixture to boil. Remove from the heat and stir in until smooth:
Stir in:
Mix well to combine. Refrigerate the ice cream base until cold, overnight if possible, or quick-chill in an ice water bath.
Pour the base into an ice cream maker and freeze as directed. Transfer to a container with a tight-fitting lid and freeze for at least 4 hours to harden.