Here's a recipe for those of you who own a microwave:
2/3 cup brown sugar (muscavado or soft brown) 2 eggs 100g melted butter 3/4 cup self raising flour 1/4 cup milk 3 tablespoon damson jam and a few chopped plums 1/4 cup good quality cocoa powder
Mix together sugar, flour, cocoa, eggs and milk. Add melted butter. Put jam and chopped plums in the bottom of a microwave proof jug, pour mixture in on top. Cook, covered with a plate, in the microwave on high for 4 minutes. Let it stand for a minute, then cook for a further 4 minutes.