The Cros Twist is a one handed variation of Paul Harris' Bizarre Twist from The Art of Astonishment volume 1. It's a strikingly visual effect where the Ace of Spades is trapped in between two cards and then magically flips over with a shake. The magician repeats the trick again, but this time it has an even greater effect.
Credits: Paul Harris, Daniel Cros
Source: Art of Astonishment vol. 1