Junie B Jones and the Yucky Blucky Fruitcake, Book 5 by Barabara Park

Meet the World's Funniest Kindergartner--Junie B. Jones! It's Carnival Night, and Lucille has already won a box of fluffy cupcakes with sprinkles on them.

But when Junie B. wins the Cake Walk, she chooses the bestest cake of all--the one wrapped in sparkly aluminum foil.

How was she to know it was a lethal weapon?