1. Begin to mix the cake and frosting together with your hands working until the mixture is evenly moistened. You want the cake mixture to easily hold together, but still retain a little texture. My personal preference is to have some “crumb” left to the crumb, so that it is not just a gooey ball. Of course, tastes vary, so if it seems as if the cake mixture is too dry, or you like a gooier taste, add more frosting until you're happy with the taste and texture.
2.Make sure that when you're finished mixing, the cake holds together well when you squeeze it into a ball.