I tried making a peanut butter chocolate brownie in a mug the other day, but it tasted terrible!

I've found a ton of in-a-mug recipes online, but I've had to have one that actually works/tastes good. Does anyone have any suggestions?

https://www.youtube.com/watch?v=P4ydcDbqyW4
That one works for me, just microwave it for one minute, stick a fork in it to test it, and if it doesn't come out clean microwave it for another. Keep doing that till the cake isn't liquid, 'le~!