Stick your mug in the microwave and cook for about 1 minute. If cake is not done after 1 minute, zap it for an extra 15 seconds.
Allow cake to cool slightly.
Enjoy immediately, with whipped cream and caramel sauce.
Notes
Got tired of inconsistent results, so I replaced my old recipe with a newer version from Kirbie's Craving's new mug cake cookbook. Here's a link to my new post if you want to see more recent, updated pictures.
Recipe by Just Putzing Around the Kitchen at https://www.justputzing.com/2011/12/gingerbread-mug-cake-egg-less.html