Step 1: Grease your mug with little butter.
Step 2: add dry ingredients to the mug, and mix well.
Step 3: add egg to the mixture in your mug.
Step 4: be sure to mix it well to avoid any pockets of flour in the corners.
Step 5: pour milk and oil and mix well. Add the vanilla extract and chocolate chips.
Step 6: microwave for 3 minutes on maximum power (1000watt).
Step 7: wait until the cake stops rising, and sets in the mug.
Step 8: if necessary, run a knife around the sides of the mug, and tip the still warm cake out of the mug and onto a saucer.
Step 9: use little leftover mango pulp as topping.