I know they say Grasmere is the place for Gingerbread, but if you happen to be in Ambleside and find a little cafe I think called the Apple Pie (on the right as you walk into Ambleside from the main carpark) they do THE best gingerbread we've ever had and also the biggest bestest sticky buns in the world, very generous on fruit and cherries.
Both great for when you need energy and something yummy on your walks.