In an individual serving bowl add flour, sugar, chocolate/cocoa powder and salt. Mix.
Add water and vegetable oil. Mix well.
Microwave for 30 seconds on high.
Dust with powdered sugar (optional)
Video
Notes
The time needed on the microwave can change according to its power. If you have a powerful one, maybe start with 25 seconds and check. If you have a less powerful microwave oven, you might want to leave a little bit longerAdapted from Food Network