Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch baking dish.
Place the dressing in a shallow dish or bowl for dipping. Do the same with the cornflakes crumbs or breadcrumbs (see Cook's Note). Dip the chicken breasts, one at a time, in the dressing, then in the breadcrumbs to coat.
Place chicken breasts in prepared baking dish. Bake in the preheated oven for 25 to 30 minutes, or until an instant-read thermometer reads 165 degrees F (74 degrees C).