Start whipping cream with mixer until soft peaks form.
Slowly add remaining ingredients.
Continue beating until stiffer peaks form.
Put mixture in freezer.
After 20 minutes, remove from freezer and stir with fork to break up frozen areas around edges.
Keep checking mix every 20 minutes and stir until it’s cold enough and the right consistency.
Video
Notes
If you have an ice cream maker, the mixture can be turned frozen much faster by churning in a machine.A blender can be used instead of a mixer if it's able to whip the cream to soft peaks.The unsweetened cocoa powder can be left out and more vanilla extract or vanilla bean added to make a vanilla frosty.