Combine unsweetened chocolate, milk and 7 tablespoons sugar in top of double boiler over simmering water. Cook, stirring occasionally, until chocolate and sugar are melted. Remove from heat and let stand 10 minutes.
Drop egg yolks into chocolate mixture. Using wire whisk mix until blended.
Beat egg whites with mixer until stiff. Add remaining 1 tablespoon sugar and continue beating until blended. Using wire whisk, add 1/3 of egg-white mixture to chocolate mixture and whip until blended. Gently fold remaining egg whites into mixture.
Butter 6 individual souffle dishes covering entire inside surface and rim. Sprinkle with granulated sugar.
Fill each souffle dish to rim with chocolate mixture. Bake 20 minutes at 350 degrees. Remove from oven, dust with powdered sugar and serve at once with dollop of whipped cream. Makes 6 servings.