step 1
Add dry ingredients to mug, mix well with a fork.
step 2
Add egg, mix throughly.
step 3
Pour in milk, oil and vanilla, mix well.
step 4
Add chocolate chips if desired. Push a dollop of peanut butter into the center of the batter if desired.
step 5
Put mug into microwave and cook for three minutes on 1000 watts.
step 6
Cake will rise over top of mug. Allow to cool for 2 minutes.