"Happy Hallowmwww." That's what your freshly decorated cake says after you've transported it to the costume party and removed its aluminum-foil cover —and seemingly half its frosting. The new Single Handle Covered Pan from the Good Cook (9 by 13 inches, $10, www.goodcook.com) lets you carry sheet cakes and casseroles straight from the oven to the party. The nonstick pan features a lid with a collapsible handle, and it snaps on tight — secure enough even to protect treats from curious little fingers and hungry little mouths.