Hi Adelle! I can't think of a better place to celebrate a birthday than at Disney! Be sure to get him a birthday button when you check in to your Disney
resort or at any Guest Relations location. If you let your server know it's your son's birthday they will usually bring over a cupcake with a candle in it, free of charge. And yes, they even do this at breakfast, which my daughter experienced first hand at the Cape May character breakfast buffet!
If you would like to have him receive a 6" non-customized birthday cake, you need only tell the host upon check in at your dining location as they do not need advance notice for these cakes. They are $21 and come in chocolate or vanilla.
If you would prefer a customized cake, there are a few different options available, which you can find out more about by calling the Disney World cake hotline at (407) 827-2253. Customized cakes will need 48 hours notice to be ordered.
There is also a new option - a "My Mini Surprise" cake which comes in a pirate treasure chest or princess jewelry box design and is available at most family table service dining locations for $15. Be sure to ask your host for more information. You can see some cake designs and even more birthday celebration ideas at Disney World's
Customize Your Celebrations page.
Since T-Rex is not operated by Disney they do not offer the options mentioned above. You can call T-Rex directly at (407) 828-TREX for more information. On a side note, my kids love T-Rex - if your son is a dinosaur fan I'm sure it'll be a great place to celebrate turning 8!
The most important thing to remember about celebrating a birthday at Walt Disney World is just to tell everyone you meet! You never know what kind of surprises you may receive. Happy Birthday to your son and let us know if you have any other questions! ~Suzannah