Hi there! I have a friend who has asked me to make a stacked book cake for a graduation this weekend. I am wondering about making my own MMF and using that. I have only ever made the MMF once and I wasn't that thrilled with the results. Does someone have a great recipe they reccomend? Can I add Tylose to it to make the book cake?

Would love to have your opinion.

I prefer the Michele Foster fondant (MFF - recipe in the recipe section here) to MMF. It doesn't use marshmallows and I find it easier to make. You need something stiffer that fondant for the book cover, and your idea of adding tylose (CMC) to the fondant for that is exactly what I do for stacked books. Also, look for cserwa's excellent post on stacked book cakes - it has a summary of some excellent suggestions for making these cakes. Here's the link:
http://cakecentral.com/cake-decorating-ftopict-628199-stacked.html+book

I have never made a stacked book cake, but I only use marshmallow fondant on my cakes. I don't see why you couldn't use it. It firms up and becomes slightly hard just like regular fondant. I have heard of people adding tylose powder, and I have heard of people adding gumpaste to make a stiffer fondant. I use 10 ounces of marshmallows and add 1 tablespoon of water. Microwave on high for about 1 minute and stir. Microwave for 1 more minute and stir until all lumps are gone. I then add any coloring gels and flavor/extracts (about 1 tablespoon) and stir those in. Then I add approximately 2 pounds powdered sugar. I say approximately, because the amount will depend largely upon the humidity factor. I just keep adding powdered sugar until the "fondant" is a stiff play-doh like consistency. Let it rest overnight for the best results. If you try to use it immediately, you are apt to have a lot of difficulty working with it as the sugar hasn't completely melded with the liquid.