Phases of the Moon w/Oreo Cookies

I found a cute hands on chart of the phases of the moon on Pinterest at
http://cuegly.blogspot.com/2011/09/75-kid-activities.html 
It was done on a styrofoam plate with cookies attached to show the 8 phases of the moon.  It looked like a lot of fun.

We tried it last week with a few modifications:
I used cardstock instead of a plate, since the plate looked crowded & difficult to write on.

 

One thing  I discovered was that  by the next day stains appeared on the cardstock.  They looked like grease spots, but felt completely dry.  Another thing I learned is that apparently they don't make Oreos like they used to.  I remember the filling being firm.  In "the old days" it was easy to twist the cookie apart and get one "clean" half and one frosted half.  It was also easy to scrape away part of the filling in a clean swoop.  The filling is different nowadays.  It is more like soft, sticky frosting.  It was difficult to twist the cookies apart perfectly, and very difficult to scrape the frosting into the desired shapes.  Fortunately, I had two volunteer moms who helped me prepare the proper shapes.  I had anticipated that the kids would do this themselves, but it was actually quite tricky for the adults to handle the cream filling.  

This project would be entirely appropriate for an extra credit at home project, or a home schooling project, but was not easy to manage with 22 students.  (Fortunately, several kids were absent or I would have had 25.)

I will give it another try next year.  I am wondering about using a different brand of cookie.   Apparently Trader Joe's sells this type of cookie made from sugar rather than high fructose syrup.  Or maybe stale cookies would work better, but eating the broken cookies would not be so fun.....  I think I will also use cut file folders for the backing since they are heavier than cardstock.

If you try this, please let me know if you discover a secret for working with the Oreos.  Obviously the styrofoam wouldn't show the "grease" spots, but I didn't want to pay for large styrofoam plates on top of buying all of the Oreos.