Mix all of the ingredients together except the Ghirardelli chocolate pieces in a separate bowl.
Pour into a lighty greased microwave safe mug.
Drop the broken chocolate pieces in the center of the batter.
Bake in the microwave for approximately 65 seconds.
Every microwave varies in heat and cooking times, so you will have to watch it closely and may have to test sample a couple of times before you know for sure the timing for your cakes. I microwave mine for 60 to 65 seconds each time and they come out perfeclty!