Mix together all ingredients except for chocolate in a mug until smooth. If you’re not averse to raw egg, test a bit of the batter for sweetness. Sprinkle chocolate on top of batter.
place mug in microwave. Because all microwaves are different, start by microwaving for 60 seconds and check for done-ness, then keep zapping for 10 second increments until cooked to your liking. I like mine molten in the centre so i take it out when it’s still a bit wibbly in the centre. Keep in mind the dark choc will melt and look like wet batter!