Chocolate Cake in a Mug

This is a from a good family friend and sounds DIVINE! I have made something similar and I'm sure this will not disappoint. Thanks, Kelly!

Enjoy!

INGREDIENTS:
1 large coffee mug
4 tbsp flour
4 tbsp sugar
2 tbsp unsweetened cocoa
1 egg
3 tbsp milk
3 tbsp vegetable oil
small splash of vanilla
3 tbsp chocolate chips (optional)

DIRECTIONS:
Spray mug with cooking spray, then mix together all the ingredients in the mug, in the order given: first mix all dry ingredients, add egg and mix, then milk, oil and vanilla and mix well. Stir in chocolate chips. Place mug in microwave, and cook on high for 3 minutes (more or less depending on your microwave). The cake will rise over the top of the mug, but don't be alarmed. It will not overflow. Allow to cool a little then eat it with a spoon directly from the mug, or tip out onto a plate.