Work Cupcakes

A month or so ago it was one of Ammon's coworker's birthday, but he didn't tell anyone. I found out because I'm friends with his wife on facebook. So the next day Ammon took cupcakes to work and hung up a "Happy Birthday" sign but printed off the word "yesterday" and hung that at the end. Evidently Ammon's coworkers decided they like celebrating birthdays with cupcakes. So I've made cupcakes 2 more times since then. The second time I made them, Ammon told me some hobbies of the coworker whose birthday it was. I wanted to make themed cupcakes, but didn't have the stuff to do it that night. This time I had a couple of days to plan. Can you guess what this coworker's hobby is?

Golf!
I had a lot of fun making these!