Put butter into mug and microwave for 10 seconds to melt.
Add in egg and milk and lightly beat with a fork until combined.
Add dry ingredients into mug and beat with your fork until mixed through.
Press a whole Cadbury Creme egg into the middle of the batter. Top with 1/2 another Creme Egg for extra gooeyness.
Place mug in the microwave and cook for 1 minute on medium heat.
The pudding should be risen and still slightly molten in the middle. If still undercooked for your liking, cook it further in 10 second bursts in the microwave.