No matter what kind of cake you've made, if it turns out too dry, you can moisten it with an appropriately flavored liqueur or syrup. Use a skewer.
I baked a chocolate cake which came out way too dry. Is there a good way to moisten it? I was thinking of drizzling it with Kahlua or spritzing it.
A dry fruit or butter cake can be improved by using one of the methods described steam and force it back into the cake, helping to soften and moisten it again.