sugar-plum vs sweetie pie

sugar-plum

noun
  • Term of endearment: sweetheart, darling. 

  • A round or oval sweet/piece of candy made of boiled sugar. 

sweetie pie

noun
  • A sweetheart; a beloved person. 

How often have the words sugar-plum and sweetie pie occurred in a corpus of books? (source: Google Ngram Viewer )