Now keep in mind it's been 10 years since I worked there but yes you used to be able to get grapefruit cake at Starring Rolls. It was in the case with the other goodies. Not sure now since it's changed but it never hurts to ask. And if not go into the Derby and ask at the podium if you can get a slice to go. We used to do that a lot.
My DD loves the GC and we have been able to get it everytime she asks. We have never seen it in the glass case. They always have to go over to Brown Derby to get it.
I did that but it was not a snack credit. It cost over $7.00. It tasted a little stale and I did not eat it. I'm still glad I tried so I would stop obsessing over it, but now I get the fruit tart or cupcake which is much better to me.