Add your butter and sugar to a bowl.
Add your egg and vanilla.
Now mix that.
Add your flour, cocoa powder, baking powder, and baking soda to a bowl.
Mix that all together. And gather up the coffee, your flour mixture, and butter mixture.
Now add 1/3 of your dry ingredients to the butter mixture and mix.
Now add 1/2 of the coffee to the batter.
And mix that.
Repeat until all of the ingredients are gone.
Microwave for 1-2 minutes and you are done!