In To Kill a Mockingbird, what does Miss Maudie jealously guard?

Miss Maudie jealously guards her recipe for Lane Cake
(chapter 5 and chapter 8). Maudie Atkinson is shown to be a broad-minded woman in a
mostly narrow-minded town.  She is the female equivalent of Atticus.  Her one area of
selfishness is in the secrecy of her recipe.  Scout notes that "[Miss Maudie] made the
best cakes in the neighborhood."  Lane Cake, according to the story, is a staple recipe
among southern women, and Miss Maudie notes that Stephanie Crawford has been after her
recipe for years. In chapter 8, Miss Maudie makes this observation after she tells Scout
she plans to make a cake for Mr. Avery after a fire destroyed Miss Maudie's house where
Mr. Avery roomed. (Note:  Lane Cake is a cake made with fruit and nuts.  Many variations
of the recipe can be found.)