Hi Julia, Thanks for your speedy response. I made the cookies today and they taste great - definitely a keeper, very chocolatey. As I was making a double recipe, I replaced 3/4 cup flour with 3/4 cup Hersheys cocoa. Also added 2 tsps of vanilla. I didn't change the sugar as I thought that once I ice them they would still be plenty sweet. I had some of the regular dough in the freezer so baked the two types together using the same cookie cutters, both plain and fluted, to see if there was a difference in the spread when they baked. The only difference seems to be that the cocoa ones with the fluted cutter actually have a sharper edge and didn't spread at all, so good all around!
Thanks so much for your advice, you are a cookie maker to be reckoned with!