dulce de leche vs toffee

dulce de leche

noun
  • A South American sweet spread made from sugar and boiled milk. 

toffee

noun
  • A type of confectionery made by boiling sugar (or treacle, etc) with butter or milk, then cooling the mixture so that it becomes hard. 

  • A small, individual piece of toffee. 

  • Any kind of sweets; candy. 

verb
  • To coat in toffee. 

How often have the words dulce de leche and toffee occurred in a corpus of books? (source: Google Ngram Viewer )