In a high speed blender, add your milk and cocoa and blend until combined. Add the powdered sweetener and blend once more.
Pour into glasses filled with ice, or refrigerate until cold.
Notes
TO STORE: Chocolate milk should be stored in the refrigerator, in a glass jar or bottle. It will keep well for up to 2 weeks. TO FREEZE: Place the milk in shallow containers and store it in the freezer for up to 6 months. Thaw the milk until it is a liquid form, before drinking.