Nutella Mug Cake

I made this two days ago and then again today. The recipe is easy and it turned out  to be very good, with the exception of the cup size. The first time I did it, I used a regular coffee mug (similar to the one shown) and sure enough it overflowed the cup. The second time, I used a bigger  mug and again it overflowed into the microwave.
I only micro-waved it for 2.5 minutes. Also, it is very rich and I ended up sharing mine with my son and husband so for me it was 3 servings.

Another yummy idea, is to add it to some vanilla ice cream for al a mode.
Thanks for the recipe Babble.com!