Mix all ingredients in a bowl, except chocolate chips.
Pour it into a microwave safe coffee mug.
Microwave on high power (mine went to 800 watts) for 1.30 mins.
Remove it and let it stand for a min.
Top with chocolate chips and serve.
Notes
1) My microwave has 800 watts. I cooked it for 1.30 mins. If you have higher power microwave, you can cook it lesser. 2)You can add nuts or chocolate chips into the batter.