That will be fun. Too bad you are getting a cold! I am at the tail-end of one, too!
Re: cinnamon - I don't think they are supposed to have spices, but a little probably wouldn't hurt anything.
You've got to give the little one something, too. I guarantee if you blow up a few balloons that they'll have fun anyway.
Can't wait to hear how it goes.
Have a happy birthday, Moose!