1 Tbs of cocoa powder, 1 Tbs of sugar, 1/2 Tbs of milk, 1/2 Tbs of vegetable oil, 1 large egg, 1 tea spoon of vanilla extract (optional), Chocolate chips for topping (optional)
In a microwave friendly mug, combine cocoa powder and sugar.
Add milk, oil and egg to the mug and mix all until it gets smooth.
If you are using vanilla extract then add it to the mixture and stir well.
Place the mug in the microwave and cook on high for 1-2 minutes, depending on your microwave's power.
Check the cake for doneness. If it is not cooked to your liking then cook it for another 15-30 seconds.
Remove the cake from the microwave and top with chocolate chips, if desired. Let cool for a minute and enjoy your delicious microwave chocolate mug cake!