You should really try Martha's recipe next time. It's much, much, much better, IMO and is what I use exclusively.
A hint, though, when you add in the dry ingredients, only mix until "just" combined and that's it. Even though they are "only cookies", I don't like to develop the glueten in them too much and this way they are very tender and buttery and delish!
I have also rolled them out on powdered sugar--but I prefer rolling them between 2 pieces of parchment.
Also--the length of bake time is really going to depend on what you are cutting them with and how you are rolling them. I like my cookies to be really thick, so naturally they take longer to bake. When I'm doing them, I really watch the first batch carefully and decide how long it's going to take. Remember also that they will finish baking on the sheet out of the oven in the 1 to 2 minutes you have them sit before removing them to cooling racks.
I'm glad that these were just practice for you! I always like to practice with new recipes first.