4 egg yolks
1 c. heavy cream
1 c. (packed) brown sugar
3 c. half-and-half or light cream
1 1/2 tsp. vanilla extract

In heavy, medium, nonaluminum saucepan, whisk together the egg yolks and brown sugar until thick.

In another medium saucepan bring the cream and half and half just to a boil over moderate heat. Gradually whisk the hot cream into the egg yolk mixture in a thin stream.

Cook over low heat stirring constantly, until the custard is thick enough to coat the back of a spoon about 6 minutes. Do Not Boil.

Immediately strain the custard into a medium bowl. Stir in the vanilla and cool to room temperature, stirring occasionally, about 30 minutes. Cover and refrigerate until very cold, at least 5 hours.

Pour the cold custard into an ice cream maker and freeze according to the manufacturer's instructions. Let the ice cream soften slightly before serving.