The Stud Muffins food trailer finally is up and running at Proline Concrete in Dorr. It is Monday-Friday from 7 to 10 a.m. for breakfast pastries, coffee, and gourmet cupcakes. The menu will continue to expand over the next few weeks, and cupcake flavors, as well as other items, will rotate weekly. Owners will be posting flavors of the week and other updates every week on their Facebook page.