Summarize this article in one sentence.
You can create even zig-zag lines by moving your arm back and forth in a uniform way across the entire sheet of cake balls. To ensure a hard coating and a more uniform appearance to the topping, place the cake balls in the freezer or refrigerator for about an hour or two.

Summary:
Drizzle additional melted chocolate on top. Chill the cake balls again. Finished.