First off, to answer your question
1. Yes they only grow where there is space for them to grow, they won't grow inside of the cake. If you cut open a cake that has fruited a few times, you won't see any pinning.

2. Yes you can slice up your cakes. I use to cut my cakes into slices before I started to crumble them in my casings.

You can slice them up like a cucumber. I use to get 5 slices per 1/2 pint jar. I never thought of slicing them up then putting them back in a terrainum. If you're dealing with PF spores usually I try to get one REALLY good flush, after that the yeild dies down a significant amount.

On average,I get 1 great flush, then an ok second flush, and sometimes not even a third.

WOW! This is a great idea!! Has anyone ever tried this before? Any success stories or failures? I'd like to hear them:-)

I have some cakes which will be close to birthing soon...I might have to give this a try :-)