Apple-pie bed

from The Collaborative International Dictionary of English v.0.48

Apple pie \Ap"ple pie`\
   A pie made of apples (usually sliced or stewed) with spice
   and sugar.
   [1913 Webster]

   {Apple-pie bed}, a bed in which, as a joke, the sheets are so
      doubled (like the cover of an apple turnover) as to
      prevent any one from getting at his length between them.
      --Halliwell --Conybeare.

   {Apple-pie order}, perfect order or arrangement. [Colloq.]
      --Halliwell.
      [1913 Webster]