In a microwave safe MUG:
Add dry ingredients to mug, mix well with a fork.
Add egg, mix thoroughly.
Pour in milk and oil and vanilla, mix well.
Add chips, if using.
Put mug in microwave, and cook for three minutes on 1000 watts.
Cake will rise over top of mug--do not be alarmed!
Allow to cool a little; tip onto a plate if desired.