CLASSIC VANILLA BEAN ICE CREAM
One 4-in [10-cm] vanilla bean
2 cups [480 ml] half-and-half or whole milk
4 egg yolks
2/3 cup [130 g] sugar
1 cup [240 ml] heavy cream
Prepare a large bowl or pan of ice water, to be used as an ice bath.
Split the vanilla bean in half lengthwise and scrape the black seeds into the top of a double boiler or a heatproof bowl. Add the pod and the half-and-half, and heat over simmering water until steaming. Whisk the egg yolks in a bowl until blended, then whisk in the sugar.
Whisk in some of the hot half-and-half and then pour the yolk mixture back into the top of the double boiler. Stir and cook over the simmering water until the mixture forms a custard and coats the back of the spoon, about 10 minutes.
Immediately set the custard-filled pan in the ice bath and stir the custard occasionally until it cools to room temperature. Transfer to a container and stir in the cream. Cover and refrigerate until thoroughly chilled. Remove the vanilla pod with a fork.
Freeze the chilled custard in an ice-cream maker according to the manufacturer’s instructions. Transfer to a container, cover, and freeze until firm, about 2 hours before serving.