We just had dinner there for my mom's 60th B-day and we got a cake -- I think was 6".
It was chocolate cake/chocolate frosting and was really good. Then they brought us their regular dessert, too!
We ordered a cake for DS's 4th birthday last September...I just added it when I made the ADR and then reminded them at the podium when we checked in. It was okay tasting and DS just loved it. I believe it was either $11.50 or $12.50 and I do remember they applied the DDE discount to it.