How To Make Britain's Luxurious Confection, Millionaire's Shortbread | America's Test KitchenAmerica's Test Kitchen LogoCook's Country LogoCook's Illustrated LogoAmerica's Test Kitchen LogoCook's Country LogoCook's Illustrated Logo

Britain’s triple-decker combo of buttery cookie, sweet caramel, and dark chocolate makes a perfect holiday gift. But only if every layer is flawless.