be used the same as a Kopykake projector. I seen the portable one in the classifieds but have no idea if it can be used the same way

Anyone?

I'm not sure. A typical classroom projector takes an image on a transparency and shoots it onto a wall. I'm not sure if you could sit it on its side so that the projecting mirror aims down at the table. Focal length might be an issue. I've used one to transfer large images to a wall for tracing but I'm not sure how small you could narrow the images to use on cakes/cookies.

HTH
Kristy