1. For about 3 1/2 cups, in large saucepan, beat together 4 eggs or 8 egg yolks, 1/2 cup sugar and 1/4 teaspoon salt, if desired.
2. Stir in 2 1/2 cups skim or 1% low-fat milk.
3. Cook over low heat, stirring constantly, until mixture is just thick enough to coat a metal spoon with a thin film and reaches 160° F. Remove from heat.
4. Cool quickly by setting pan in bowl of ice or cold water and stirring for a few minutes. Stir in 1 1/2 teaspoons vanilla.
5. Press plastic wrap onto surface of custard.
Refrigerate until thoroughly chilled.
