Danish pastry vs sponge cake

Danish pastry

noun
  • A sweet and flaky yeast-raised roll made from a dough using butter or margarine and filled with remonce (butter and sugar) or custard. 

sponge cake

noun
  • A light, soft, baked dessert (commonly layered with cream and jam) that is typically made with flour, sugar, baking powder and eggs, and has a firm, yet well aerated structure, similar to that of a sea sponge. 

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