For those worried about Google coming to blows with Nestle (How we still lament the demise of Rowntrees)...

From Wikipedia 'kit kat':

Use of the name "Kit Kat" or "Kit Cat" for a type of food goes back to the 18th century, when mutton pies known as a Kit-Kat were served at meetings of the political Kit-Cat Club in London.

Now a mutton pie doesn't quite sound as sweet a desert.