Preparation / Directions:
Mix 1/3 cup sugar, the cocoa, and flour in 1-1/2-quart saucepan. Gradually stir in milk. Heat to boiling, stirring constantly; remove from heat. Beat egg yolks with fork in small bowl. Beat in about one-third of the cocoa mixture. Gradually stir in remaining cocoa mixture. Stir in margarine and vanilla; cool slightly.Place oven rack in lowest position. Heat oven to 350 degrees. Butter and sugar 6-cup souffle dish. Make 4-inch band of triple-thickness aluminum foil 2 inches longer than circumference of dish.
Butter and sugar one side of band. Extend dish by securing band, buttered side in, around outside edge.Beat egg whites, cream of tartar and salt in 2-1/2-quart bowl until foamy. Beat in 3 tablespoons sugar, 1 tablespoon at a time; continue beating until stiff and glossy. Do not underbeat. Stir about one-fourth of the egg whites into cocoa mixture. Fold in remaining egg whites. Carefully pour into souffle dish. Place dish in square pan, 9 X 9 X 2 inches, on oven rack. Pour very hot water into pan until 1 inch deep.
Bake 1-1/4 hours. While souffle is baking, prepare Best Sauce. Immediately serve with Best Sauce. 6 SERVINGS; 445 CALORIES PER SERVING. BEST SAUCE Beat powdered sugar and margarine in 1-quart saucepan until creamy. Beat whipping cream in chilled bowl until stiff. Fold whipped cream into sugar mixture. Heat to boiling, stirring occasionally.