Preheat oven to 350°. In a large skillet, heat butter over medium heat. Add onion and celery; cook and stir 4-6 minutes or just until tender.
In a large bowl, mix eggs, parsley, salt, thyme and pepper. Stir in bread crumbs, apples and onion mixture. Shape into 2-in. balls. Place in a foil-lined 15x10x1-in. baking pan. Bake 30-35 minutes or until golden brown.