This is found in Epcot at the land pavilion on the first floor in the Nestle booth. Its fun and offered several times a day - the cookies are very good. I wouldn't make a special trip to do it, especially if you make cookes at home, (YMMV) but if your in the area when a session is starting the kids seem to enjoy it.
My dd5yr old Loves the cookie making at the Land and we will make a special trip there to do it for her. they give the kids chefs hats and really get them involved. She loves, loves it and we do make cookies at home. There is just something about disney cookies...