1. Place 12 heavily greased iron popover pans or custard cups in 450° F oven.
2. Crush cereal into fine crumbs and mix with flour and salt in 4 cup liquid measure. Set aside.
3. Combine well-beaten eggs, milk and cooled, melted butter. Add to flour mixture, beating until smooth. (Don't be afraid of overbeating.) Pour batter into heated pans until 1/2 full.
4. Bake at 450°F about 30 minutes. Reduce heat to 350°F and bake 15 minutes longer.
5. Remove immediately from pans and cut slit in side of each popover to allow steam to escape. Serve immediately.