If your chocolate cake is dry, there are a few things you can do to moisten it up. One simple way is to add a bit of water to the cake. You can also try adding some milk or cream. Another option is to brush the cake with syrup. You can also add frosting or glaze to the cake. If you're really in a bind, you can always put the dry cake back in the oven for a few minutes. Just be sure not to overcook it!