The process was quite complicated, involving putting tempered chocolate — meaning it has been repeatedly melted and cooled to form a crystalline structure — into a 3D printer. They had to keep the tempered chocolate at 90 degrees Fahrenheit while it was being printed into complex shapes designed to improve the crispiness of the finished product.
The results were published in a paper in the journal Soft Matters entitled “Edible mechanical metamaterials with designed fracture for mouthfeel control.” That’s a mouthful (pun intended).