S'mores - make ahead?

Anytime I see those GIANT marshmallows, I just feel that I can't pass them up.  This recently happened, and being that we don't have a fire pit at the moment, I had no clue what I would do with them.  We were able to rent out the Superintendent's boat for a little cruise, and I decided I would attempt to pre-make some s'mores for dessert.

Has anyone done this before or have any good tips on best practices for pre-made s'mores?  I looked online, but didn't come up with anything great. 

First, I sliced the marshmallows in half horizontally, and then toasted one graham cracker with chocolate and the marshmallow on top.

I wasn't sure of a better way to do this.  It toasted the marshmallow really nicely, but in some cases the crackers got a little burned.

Then, I just put a dab of melted chocolate on top of the marshmallow in order to hold the top graham cracker in place.

Finally, after they were cool, I wrapped them in wax paper and tied them up with baker's twine.  My review....the crackers were too soft by the time I served them.  I feel like there must be a better way to do this...any advice?