Add dry ingredients to a coffee mug, and mix well
Add the egg and mix thoroughly. Pour in the milk
and oil and mix well.
Add the chocolate chips (if using) and vanilla
extract, and mix again.
Put your mug in the microwave and cook for 3
minutes at 1000 watts. The cake will rise over the
top of the mug, but don’t be alarmed! Allow to
cool a little, and tip out onto a plate if