Chill bowl and beaters for 15 minutes before beginning.
Add heavy whipping cream to the bowl.
1 pint cold heavy whipping cream
Beat until just beginning to thicken. You should be able to see tracks in the cream.
Add the cocoa powder and powdered sugar.
½ cup cocoa powder, ¾ cup powdered sugar
Continue beating until whipped cream reaches desired consistency. Do not overwhip or it will begin to turn to butter.
Chill any leftover whipped cream.
Notes
Whipping cream: It's important that the cream be cold so it will whip up better.
Cocoa powder: I use regular unsweetened cocoa powder or Hershey's Special Dark cocoa powder in this recipe. I haven't tried using Dutch-processed cocoa powder in this recipe.
Powdered sugar: Please see the notes above the recipe for using granulated sugar.
Flavorings: I also have notes above about adding flavorings to the whipped cream.