These were excellent. Next time, I plan to double the recipe. I made some with cinnamon sugar on top and some with refined white sugar and just a little extra "sanding" sugar at the end (just prior to baking), which I pressed down a little to be sure it would stick. I used SACO brand powdered buttermilk but might even spring for real buttermilk the next time I make these. I found that they needed about 8 or 9 minutes in the oven, but I suppose times might vary depending on how thick you roll them and how your oven works.
This was very easy to make in my stand mixer. I put the dough in the freezer but it did take longer than 15 minutes to harden up enough to work with; it needs about 30 minutes (at least in my freezer). The dough was really soft. I also used Kate's buttermilk (liquid). The cookies tasted wonderful and have stayed soft for 3 days now. I recommend frosting them... they were amazing. I will definitely make this recipe again.