Microwave on high for 1½ - 2 minutes, depending on the wattage of your microwave. It took mine 90 seconds.
It will come out hot so beware! It will be a delicious combo of soft moist cake and rich chocolate sauce. Perfect for an impromptu dessert, or for movie night.
Notes
It makes quite a large quantity for one person. Leave the left overs in the fridge over night, and you will have a dense, moist chocolate pudding the next day for an afternoon treat!