Put the cocoa powder and a little milk in a mug, and mix well with a spoon until creamy. Mix in the rest of the milk in small batches.
Add as many marshmallows as you like to the Step 1 mug. I added 4 - 5 frozen marshmallows, but it's fine unfrozen.
Microwave it and the marshmallows will melt! (I microwave it at 900 W for 40 seconds).
Story Behind this Recipe
I wanted to come up with a drink in which I could use frozen marshmallows.
Adjust the microwave time as necessary. I sprinkled with cocoa powder, but you can also use chocolate flakes to make it look extravagant. Mix the melted marshmallows into the hot chocolate with a spoon, and enjoy!