Creamy mac and cheese with buttered panko crumbs

Each bite of this mac and cheese is crackly and silky as the crunch of toasted crumbs gives way to the riptide of cheese sauce. Typically, you only get the pleasure of crisp crumbs over mac and cheese when the whole casserole has been baked. That stiffens the mix, sometimes so much so, it ends up sliceable. But if you broil a buttered crumb top, you get both a crackly shell and a silky base -- the best of both mac and cheese worlds.