I just made a batch....I have a few tricks to help combine the dough better, because it does get crumbly. I don't know if I'm doing it right or wrong, but everyone says they taste great, and that's all that matters to me.
* My KA isn't a Pro, so the full batch is a lot for my mixer, I take it slow. I cream and add all wet ingredients, then 1 cup at a time I add the dry, mix till creamed together, then add another cup. By the fourth cup, the mixer gets kind of hot (oh, I keep the speed on, the whole time between 2 and 4). Then when I add the rest it takes longer because the dough likes to sit above the paddle (I hate it when it does that). So I scrap it down, and at this point I add about 1/2 cup dry. Let it combine the best it can.
*Next, I take my sila mat, I form little softball size balls of dough. You REALLY need to make sure it's combined. My last batch wasn't and I had dry spots when I rolled it out. I think I make out 4 or 5 balls. Squeeze and get all the floor combines. Then with the mat, combine all the balls together into a big one. I wrap it and put it into a zip lock and let it chill.
I think that's all. If you have any other questions, I'd be happy to help (as long as I know them).