Grab two microwave-safe coffee mugs that can hold about 250 ml liquidÂ
Halve the quantity of flour, cocoa, baking powder, salt and sugar and add into each mug.
Mix well with a fork.
Then halve the quantity of milk, butter, and vanilla and add into each mug.
Break egg into another small bowl, whisk with a fork, and add half of it into each mug.
Stir well until all the ingredients mix well. Make sure there is no flour stuck to the bottom of the mug.
Add one mug at a time to the microwave and cook on medium heat for 2 mins.
Every microwave acts differently and mine is a very basic one with just two knobs, one for heat level (low, medium, high) and one for time. I kept mine on medium and set each mug at 2 minutes. The cake turned out perfect.
If your microwave can show power levels, etc, keep it at medium and start with 2 minutes.
You can adjust it once you take a look at your cooked cake.