The simplest chocolate dessert yet incredibly moist, easy, and the best single-serving dessert.
1. Measure the self-raising flour, caster sugar and cocoa powder into a large mug, and mix together. Crack in the egg, pour in the milk, oil and vanilla extract and whisk with a fork until no lumps of flour remain and you have a smooth cake batter.
2. Add the dark chocolate and mix briefly again, then the top with sea salt flakes. Put into the middle of your microwave oven and cook on high for 1½-2 minutes or until firm to the touch. Dust with a little cocoa powder to serve.