They also consider cost, using less-expensive chocolate to combine with other ingredients and flavors.
More than 40 works of 20th-century art from eight countries, many of which use chocolate in sexual and political contexts, will be on display.
Variants include adding granola or using chocolate instead of fruit.
Entrants must be at least 21, and the rules call for submitting a recipe using chocolate.
Often good wishes are written on the cake using sugar or chocolate.
Home cooks can also use white chocolate for its decorative advantages.
"They used white and red chocolate to make the checkered part," she said.
Another alternative is to use dark chocolate, such as 70% cocoa chocolate.
These master chocolatiers are some of the best in the world when it comes to designing and sculpting using chocolate.
Using less chocolate in the ganache also helps keep the cake on the lighter side.