Egg-Nog - Classic Cooked

Ingredients:
6 Egg 1/4 cup Sugar 1/4 tsp Salt (optional) 1 qt Milk, divided 1 tsp Vanilla extract

Instructions:
In large saucepan, beat together eggs, sugar and salt, if desired. Stir in 2 cups of the milk. Cook over low heat, stirring constantly, until mixture is thick enough to coat a metal spoon and reaches 160 degrees F. Remove from heat. Stir in remaining 2 cu