Castle Library Book

The are objects in.

Location and Uses
The Castle Library Books are books that recorded important Recipes for the d are found inside Hyrule Castle's Library. The first Castle Library Book is situated on top of a table in the middle of the Library's bottom floor and describes the Recipe for Fruitcake. According to the book, Fruitcake was Zelda's favorite dish and helped to clear her head when she researched ancient Sheikah technology.

The second Castle Library Book is situated atop a podium in the east wing of the Library's second floor and provides instructions for Monster Cake. According to this book, Monster Cake affects one's brain and helps the consumer to plot malicious schemes.

The Castle Library Books are important for the Side Quest, "A Royal Recipe". In the Quest, a Hylian stablehand named Gotter asks Link to enter Hyrule Castle and find any Recipes that his ancestor, a chef serving the Royal Family, might have prepared.

Trivia

 * The effect of the Monster Cake allowing one to develop evil plots and the fact that it was the Chancellor's favorite dish both seem to be a reference to Chancellor Cole, Princess Zelda's retainer in who plotted to betray her and resurrect his master, the Demon King Malladus.
 * As with other recipe books, the text reads "April First," "Today was a dry hot and sunny day," "I went to school," and "This diary is very important document" in BotW: on the first page. The second page reads "How To Cook."