1 cup dark corn syrup
1/2 cup white sugar
1/2 cup whipping cream
1/4 cup white sugar
1/2 teaspoon salt
7 tablespoons butter or margarine, melted
1 egg yolk
2 1/2 teaspoons distilled white vinegar
1 teaspoon lemon juice
1 teaspoon milk, or as needed
salt and pepper to taste
In a bowl, combine dark corn syrup and sugar. Mix well, then stir in cream and boiling powder. Warm liquid to between 230 and 240 degrees F (120 to 130 degrees C). Remove from heat and whisk in lemon juice.
In small saucepan or double boiler, combine egg yolk, vinegar, lemon juice and milk. Stir well to coat egg mixture, then pour hot liquid over egg mixture. Cook over medium-low heat, stirring occasionally, until mixture thickens.
Cool completely in glass bowl. Chill until serving.