Place all ingredients - the cream, cocoa powder, powdered sugar and vanilla extract - in a large mixing bowl. (see note)
Using a hand held electric whisk, beat just until you reach stiff peaks, usually only a few minutes. (see note)
Your cream is now ready to dollop or pipe for your dessert.
Notes
I don't sift my powdered sugar and cocoa powder in this recipe. If yours are particularly lumpy, you may want to sift them first to remove any hard or unmanageable lumps.You can also make this recipe using a stand mixer fitted with a whisk attachment. If using this, you'll want to beat on a medium-high setting until your beaters are leaving tracks in the cream. Then reduce the speed and watch carefully for the formation of stiff peaks.Alternatively, whipped cream can be made by hand with a whisk. This usually takes significantly longer and requires constant speedy manual whisking.Troubleshooting overbeating: if you've over beaten and your cream has become stiff, you can add cold milk to this (about a tablespoon at a time), whisking slowly. This will loosen the cream and return it to a smooth consistency.