This should probably also come with a warning because it is way too easy! You're now only ever going to be about three minutes away from cake!
I felt like something sweet after dinner so decided to make cake-in-a-mug. I first saw this on Breakfast. This is the original recipe but I use melted butter instead and don't worry about the vanilla or the chocolate chips. I also don't really worry about measuring it. I just kind of melt a bit of butter in the mug, then put in a couple of dessert spoons of sugar, cocoa, flour and caster sugar and a little baking powder (but you can use self raising flour or probably don't even need it). Then I cook it for a couple of minutes until it looks about done. You can't really get easier than that.
This is the photo before it is iced.
And this is once it has been iced.