Pour the cocoa powder into a mug.
Stir the cocoa powder with a fork while adding milk, little by little until the cup is full. There will be some cocoa powder on the top- that's okay.
Microwave on HIGH for 90 seconds.
Remove from microwave. The cocoa powder on top should have either turned into a custard sort of thing or a syrup. Take a fork and stir it again, breaking up the cocoa on top.
Add toppings. Enjoy!