I saw this on a blog today and just had to go try it immediately! I cased it almost exactly. The instructions with a great photo tutorial are on Kelly Roses blog here. I even used the same papers inside for my cake layers. There are so many talented people around that are kind enough to put their tutorials and things out there and that makes coming up with cute cards to give so much easier.
I just started as a Stampin' Up demonstrator at the end of June and I do not own a Stamp-a-ma-jig yet so after stamping about 5 cakes that came out lopsided, i ended up trimming the rubber on the top of the base cake and the bottom rubber of the upper layer stamp and putting them both on my clear block at the same time which worked very well except there was a tiny gap left and I just took my midnight muse marker and drew the line the rest of the way.
If you are interested in placing an order you can order 24/7 on my website or if you want to have a workshop please email me! I can do in home workshops if you are local or if you would like to earn the free products but do not live near me, we can do a virtual workshop!