It is an example of a new trend in desserts: blood. This article from the Globe and Mail ("You eat meat, so why not blood?") gives the rundown on bloody meals. It points out that blood is a common ingredient outside of North America.
A chef named Brandon Olsen says, “I enjoy blood. I think blood is a great vessel for culinary expression. When I look at The Learning Channel, at all those surgery shows, that’s when I get squeamish. But working with animals, no.”
One chef even argues that if you’re going to kill an animal, using its blood is “the responsible thing to do.” Yeah! So for Halloween I might try some chocolate blood ice cream. One chef says that it’s “a rich, chocolate-tasting ice cream that is delicious and good for you.”