Take a bowl, add refine flour ,baking powder ,baking soda ,coco powder,sugar ,veg oil.
Now Add milk gradually and make thick paste ,then add vanilla essence and mix it well.
Grease a coffee mug with little oil ,pour cake batter into the coffee mug, put it in microwave.
Microwave it for 2 minutes, insert a spoon Inside the cake, if it does not stick, means cake is done