The kids wanted cake any cake, this cake came to the rescue appropriately named 'last minute chocolate cake'. The original recipe is from Ruth Reichl's book. Almost the texture of a brownie with a very chocolatey but not too sweet taste.
Elaborate recipe is here. I added chopped walnuts and skipped the orange juice. Raisins or currants would be a good addition too.
Takes less than 20 minutes to do the prep work. Bake and voila, cake is ready in an hour.