Place cauliflower in a saucepan with a small amount of water. Cover and cook for 5-10 minutes or until crisp-tender; drain.
In a small resealable plastic bag, combine flour, garlic powder, paprika and pepper. Place cornflake crumbs in another resealable bag. Lightly beat egg whites in a shallow bowl. Toss the cauliflowerets one at a time in flour mixture, then roll in egg whites and coat with crumbs.
Place on a baking sheet coated with cooking spray. Bake at 425° for 15-20 minutes or until golden brown. Serve immediately.