I've never made a bad batch of fondant, but then, I've never made chocolate fondant! Until today...

I goofed up and added too much cocoa, I think. The fondant looked fairly normal at 3/4 cup dark cocoa, and tasted really great too. But I had taken another 1/4 cup out of the can, so I tossed it in there. I didn't think it would hurt it because I still had at least a couple cups of sugar left. MISTAKE!! It got really dry and crumbly instantly.

So, I took it out of the bowl and worked in at least 1/2 cup shortening and not quite that much glycerin and it has smoothed out some, but when I knead it, it cracks open. I've not seen any other batches do this. I went ahead and put it away to rest, but I don't believe it will roll out properly tomorrow.

Any suggestions on saving this batch?

Any suggestions on what to do or amounts to use when I start over (feel pretty sure I will have to!) ?

Cocoa works different than sugar - meaning you don't need as much cocoa as sugar.
What I would do - start a small batch MFF, meaning ca. 4 Tbsp. milk or cream, 1 Tbsp. gelatin, 1/2 cup corn syrup, omit butter or crisco and glycerin (because you have it there already).
Take small batches from your old fondant and kneed the new "base" in it.
Kneed it all well together. Let it rest an hour and examine it again.

Here you should be pretty near to the right consistency.

If still to stiff, knead some glycerin in it (no more than 3 Tbsp.). In this phase you need to eyeball it, because you don't know how much is missing from original recipe.

If it is still stiff, start adding crisco and glycerin (one tablespoon of each at time).

For the next time - Add the cocoa first when the mixture is still hot. It dissolves the cocoa better and it gets even darker. 3/4 cup looks about right. Cool it and only than start to add sugar.

Thanks so much - I will try your suggestion today! Live and learn...