I am taking the Clean and Simple Cards 3 class over at Online Card Classes, and this technique is layered die cuts. I used the Shell Set dies from Impression Obsession. (DIE077-W), and I used Distress Inks and Markers to colorize the cut outs.
This technique creates a single layer card that appears to have layers. I did add the pearls and gems–the card demanded this! So, it is not exactly a single layer.