Happy birthday

So it was my friends birthday yesterday and she put on a BBQ which was great, got to meet her ex as they are thinking about trying again and being a proper family and some of her other friends who she talks about.  The kids are great friends with her kids so they were happy to play and amuse themselves and she had baked a Chocolate Mud Cake and now the boys are asking me to do one at home but for the life of me I can't find a good recipe.