flapjack vs griddle cake

flapjack

noun
  • A pancake. 

  • A bar made of (though not limited to) rolled oats, butter, golden syrup, and brown sugar, baked in a tray. 

griddle cake

noun
  • Synonym of pancake 

How often have the words flapjack and griddle cake occurred in a corpus of books? (source: Google Ngram Viewer )