My first choice would be sweet dark cherries, which are the type of cherries found in the Black Forest in Germany and many other countries. Bing and Ranier cherries are also acceptable choices. I'm not a fan of Sour Cherries but if you enjoy them, those could also be used. In a pinch, you could use cherry filling (pie) to make this cake, but don't even think about using maraschino cherries. That would be a terrible choice for this Black Forest Cake Recipe.