Preparation

• Prepare the soufflé dishes:
  Cut parchment or wax paper into 6 strips, each 3 inches wide by 12 inches long. Wrap a strip around the outside of each soufflé mold and secure with transparent tape or a rubber band to form a raised collar extending about 1 1/2 inches above the edge of the mold. Place the molds in the refrigerator.
  Wash, hull, and slice the strawberries if fresh, or defrost the package of quick- frozen strawberries in hot water or in a microwave oven.
  Process to a puree in a blender. Strain the puree through a fine sieve over a small bowl. Refrigerate.
  Place the egg whites in a clean mixing bowl and add the cream of tartar. Stir the sugar and water in a clean grease-free saucepan. Place over high heat.
  Begin immediately to beat the egg whites using preferably a standing electric mixer, slowly at first, then increasing the speed moderately. When the sugar syrup reaches the desired temperature of 234 to 238 degrees F (soft ball stage *), remove it from the heat. By then the egg whites are medium stiff. Increase the speed of the electric beater while pouring a steady stream of the syrup into the whites. Continue beating for 5 to 6 minutes.
  Transfer the egg white mixture to a clean mixing bowl. Refrigerate. Wash the mixing bowl. Rinse under cold water, and dry. Pour the cold cream in the bowl. Whisk using the electric beater until whipped and thick. Fold half of the strawberry puree into the egg whites.
  Fold the remaining strawberry puree into the whipped cream. Then fold the two mixtures together. Divide the soufflé mixture among the 6 chilled prepared soufflé molds.
  Freeze for at least 3 hours or more. 20 minutes before serving, remove the soufflés from the freezer and place in the refrigerator. Just before serving, remove the paper collars and carefully sprinkle the cocoa powder through a fine sieve over the top of each soufflé. Serve immediately.
  
  * The simplest way to tell when the syrup reaches 235 degrees F is with a candy thermometer. But if you do not have one, use the following method: Fill a small bowl with ice water. When the syrup begins to bubble, spoon a drop into the ice water. If you can gather it into a small ball, the syrup has reached the soft ball stage, and is ready.