Virtually Fail-Proof Chocolate Souffle

 2 tbsp. butter, melted

10 tbsp. sugar

5 large eggs

2 tbsp. unsweetened cocoa powder

1 1/2 tbsp. flour

1 cup milk

2 oz. unsweetened chocolate, coarsely chopped

1 tsp. pure vanilla

1/2 tsp. cream of tartar or lemon juice

1 (5-cup) souffle dish, about 7 inches across

Set top rack of oven in middle position. There should be at least 8 inches of clearance between rack and top of oven. Preheat oven to 375 degrees.

Thoroughly brush inside of souffle dish with butter and place in freezer 10 minutes. Brush again with butter. Add 2 tablespoons of sugar to the dish and rotate to completely coat bottom and sides with sugar.

Separate the eggs, placing the clean whites, one by one, in bowl of mixer. Place 3 egg yolks in heatproof mixing bowl. (Save the other 2 for eggnog or omelets.) Add 5 tablespoons of the sugar, cocoa powder and flour and whisk to form a smooth thick paste.

Bring milk just to a boil in heavy saucepan. Whisk it in a thin steam into cocoa mixture. Return this mixture to saucepan and bring it to boil over medium-high heat, whisking constantly. Let it bubble 2 minutes, whisking constantly. It should thicken to consistency of pudding. Remove pan from heat and whisk in chopped chocolate and vanilla. Whisk until chocolate is melted and thoroughly mixed.

Add cream of tartar to egg whites and start beating at low speed. Increase speed to medium after 2 minutes, then to medium-high for 2 minutes, then to high until whites are thick, airy, cloud-like and snowy. (Consistency will be like that of soft ice cream, only much lighter.) Add remaining 3 tablespoons sugar and beat until whites are glossy, 1 to 2 minutes. Whole process of beating egg whites should take 8 to 10 minutes.

Add 1/3 of the whites to chocolate mixture and whisk vigorously to mix. This lightens the chocolate mixture. Spoon chocolate mixture over remaining egg whites and, with rubber spatula, fold just until mixed. Work as gently as possible. Spoon souffle into prepared dish, smoothing top with spatula.

Place souffle in oven. Bake until dramatically puffed and semi-set, 12 to 15 minutes. Don't open oven door if you can possibly help it. If you must open it, do so only after 10 minutes. Open it just a crack to peek, then gently close the door. A blast of cold air is enough to deflate the souffle. To test for doneness, give souffle a gentle tap on the side with a wooden spoon. It can wiggle or sway, but it shouldn't ripple.

Serve immediately, perhaps with a dollop of whipped cream. Serves 2 to 4.