Cut the cake into layers, spread the frosting between the layers and then top with the chocolate chips.
1 teaspoon Unsweetened chocolate chips
Notes
Don't overfill your mug with the batter, or it will overflow as it rises.
If your mug isn't big enough, split the batter between 2 mugs or ramekins.
I highly recommend consuming this cake on the same day. However, if you like to store it, put the cake in an airtight container in the fridge for 2-3 days.
It is important to use a microwave-safe mug or ramekin.