I should probably start by saying I'm in the camp of not expecting WDW to do anything for birthdays, nor are we a fan of birthday pins.
When you book a WDW vacation, CM's usually note birthdays. You have a few options in terms of making specific requests. Other times, WDW will give you some small tokens - at the discretion of the staff members.
the cards are one of the freebies they deliver if they have time. It's not really anything special, it's not hand signed, it's a preprinted card. I think it also had more or less an add for Photopass. As in. "It's your birthday, you might want to use Photopass!"
As for options you can buy, the ones I've looked at were pricey. You can go through the WDW florist. They deliver all sorts of flowers and gift baskets. Online the flowers don't look all that impressive, and they are $$$. the gift baskets are mostly similar. You pay $50 for a few bags of boring prepackaged chips/cookies. If you are staying on CL, you don't need bags of prepackaged cookies. In person, I've seen some amazing flowers being delivered. More than once, we've been at a WDW resort when they were changing out old flowers. (the resort décor) Sometimes we've been given the old flowers, just for talking to the CM's. Once I was standing outside a convention room where a wedding reception had just concluded. The CM was wheeling away all the table décor. The CM confessed she was about to throw all of them in the trash. She let me take as many long stem roses as I wanted. They were perfect, amazing roses.
Another option that's more fun, and kind of secret- is the special "In-room dining options." Each deluxe resort has it's own menu. I think they are open to all guests of that resort, but I think the only printed menu is the in-room menu on the desk in each room. Options are pricey. There's a service fee, plus a delivery fee. Beyond that, if you staying club level, many are redundant. As in, they will deliver to your room the same kind of cookies they have in the lounge. the same kind of cookies they sell in the quick serve. you are basically paying a premium to have WDW put them in your room. Some of the options are unique, but I don't need chocolate covered strawberries in my room when there are piles of desserts in the lounge, piles of desserts at every buffet, desserts as part of every
DDP meal, and nightly candies on my pillow. Its sugar overload. Non CL, they are a better fit.
Another option is that most TS have cakes on hand. They have a basic cake for free, and better ones that can be personalized. We've never done either. I've seen some specials WDW wedding cakes, and they can be amazing. If you are willing to pay, WDW can do amazing things!
Last, all guests can request free pins for any birthday, etc. If you wear one, you will likely have staff say, "Happy B-day" to you. I would not expect much more, but you never know. Sometimes staff has leeway to do a little extra, if they have the time. To us, being at WDW on your birthday is special enough. That said, since WDW asked at booking, I've mentioned birthdays once or twice just to see. One person got nothing, the other got the printed card.