Preheat oven to 450°. Beat 5 egg yolks in mixer or by hand. Heat the milk in a separate pan. Sift flour into light colored egg yolks and gradually blend in the hot milk. Return mixture to saucepan and heat, stirring until sauce thickens. Add melted chocolate, sugar and butter. Beat 5 egg whites and then fold egg whites into chocolate mixture. Prepare soufflé dish with softened butter and sprinkle with granulated sugar. Place in the 450° oven. After 15 minutes, run a sharp-pointed knife about the circumference of the soufflé dish, reduce oven heat to 400° and bake another 15 minutes. Decorate with powdered sugar. Serve plain or with a sauce or whipped cream. Serves 6.

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