There are a couple of different ways you can order the ears, but unfortunately no chance that they'd be waiting in your room upon arrival.
Option #1 - Disney Florist
www.disneyflorist.com, usually, they will deliver to your room after you check-in
Option #2 - there are some online gift basket companies. I don't know who is currently being recommended, but they will do personal shopping for you and deliver to the resorts front desk.
www.memoriesbybetsy.com
Option #3 - is the least expensive. Call Disney merchandising 407-363-6200. There's no upcharge, you'll pay whatever the current price is. They can be mailed home to you, or delivered to your resorts gift shop for pick up.