It is : one layer and the optional twist is B&W only.
Our sponsor is Stamploration.
For my card I cut a panel of Spectrum Noir marker paper to the exact same size as the cardbase. I had to ask our dt if it is still one layer, as I felt it wasn't. As it looks like one layer is was deemed OK, but if you were to cut it smaller it would appear a layer, so be aware.
I stamped the Dog with My Favorite Things Extreme black ink and the sentiment with Versafine Clair Nocturn ink.
I made a video for the card, I left it in real time, so with the coloring and stamping and such, it only took ten minutes.
For more information, more DT examples and or to play along the AAA Cards Challenge, see this.