1. Sprinkle gelatin over cold water in small bowl; let stand 1 minute to soften. Add boiling water; stir until gelatin is completely dissolved and mixture is clear. Cool slightly.
2. Stir together sugar and cocoa in medium bowl; add whipping cream and vanilla. Beat on medium speed of electric mixer, scraping bottom of bowl occasionally, until mixture is stiff. Pour in gelatin mixture; beat until well blended. Spoon into serving dishes.
3. Refrigerate about 30 minutes before serving. Garnish as desired. Cover; refrigerate leftover desserts. Four 1/2 cup servings.
DOUBLE RECIPE: Use 1 envelope gelatin; double remaining ingredients. Follow directions above, using large bowl instead of medium bowl.