In the past there have been cooking classes at WDW that were appropriate for teens, however nothing like that is currently being offered. I do have two sort-of alternatives for you:
1. Book a meal at a Chef's Table. This is possible at the California Grill, Citricos, and Victoria & Albert's. I must warn you that it can be difficult to get a reservation at these meals and that the meals can be quite pricey. However, I assure you that you will have the experience of a lifetime, chatting with the chefs about how and why they're preparing the dishes as they do. You can about read Panelist Kay's experience at the V&A chef's table
HERE. For more information or to make reservation, call Disney Dining at 407-W-DISNEY.
2. Reschedule your trip so that it takes place during
Epcot's Food and Wine Festival. This will be held September 25 - November 8, 2009. The Festival features cookbook authors and celebrity chefs who will meet guests and sign autographs, culinary demonstrations, cheese tastings, pastry demonstrations, and much more. I haven't seen the exact schedule for this year, but last year there were several hundred guest chefs in attendance, including TV personalities Cat Cora, Keegan Gerhard, Gale Gand, and Todd English. Try checking the independent website allears.net for more detailed information about the festival.
Good luck with your planning.