Grease a mug and set aside.
Mix all the dry ingredients; flour, baking powder, salt, and 2 tablespoons of brown sugar.
Mash the bananas and mix with eggs, 1 tablespoon of vanilla, and butter.
Mix both wet and dry ingredients together.
Pour the batter into the prepared cup and microwave for 5 minutes (time may vary depending on the microwave)
Make sure you put an eye on it. Check before the time lapses. Insert a toothpick and if it comes out clean that means it's done.
To make the glaze:
Mix milk, the rest of the vanilla extract, butter and sugar.
Microwave for about 30 seconds or until the mixture bubbles and the sugar melts.
Pour over the banana cake and enjoy.
Note:
Adjust the sugar to your liking, the glaze is optional you can enjoy it without the glaze.