Beat egg yolks in top of a double boiler until frothy. Gradually add milk, beating constantly. Stir in sugar and salt. Cook over boiling water until mixture thickens and coats a metal spoon. Remove from heat, and cool completely. Chill until ready to freeze.
Pour mixture into freezer can of a 1-gallon hand - turned or electric freezer. Stir in whipping cream and vanilla. Freeze according to manufacturer's instructions. Let ripen at least 1 hour before serving. Scoop into individual bowls, and serve.