Combine eggs, flour, and milk in top of a double boiler; beat until well blended. Place over boiling water and cook, stirring constantly with a metal spoon, until mixture thickens and coats the spoon. Remove from heat, and keep warm.
Sprinkle sugar evenly in a 10- inch cast-iron skillet; place over medium-low heat. Cook, stirring constantly with a wooden spoon, until sugar melts and becomes light golden brown. Reduce heat to low, and stir one-fourth of warm custard into caramelized sugar. Continue to cook over low heat, stirring constantly, until mixture is well blended and free of lumps.
Gradually pour caramelized sugar mixture into remaining hot custard, beating constantly with a wire whisk. Cook custard mixture over boiling water until well blended and slightly thickened. Remove from heat; cool to room temperature. Chill.
Pour mixture into freezer can of a 1-gallon h and - turned or electric freezer. Stir in whipping cream. Freeze according to manufacturer's instructions. Let ripen at least 1 hour before serving. Scoop into individual bowls, and serve immediately.