To make in a food processor: Place heavy whipping cream, pure vanilla extract, granulated white sugar and cocoa powder in food processor with whip attachment and turn on high for approximately 3 minutes or until stiff peaks form. Use immediately.
To make with an electric mixer: Place heavy whipping cream, pure vanilla extract, granulated white sugar, and cocoa powder into a large bowl, and stir to combine ingredients. Cover and chill bowl and beaters for at least 30 minutes. When chilled, beat until stiff peaks form. Use immediately.
