What is the secret ingredient in the book who stole grandmas million dollar pumpkin pie?

My Grandma Came up with (butter) and at school a boy who I dont want to tell his name unless nobody overanswers me came up with _ _ _ _ _ _. SO FIGURE IT OUT YOU MAD MONKEYS. IF YOU ANSWER OVER THIS, I WILL FORCE WIKI ANSWERS TO SHUT DOWN SO GET GOING YOU FOOLS! READ AND FIND OUT!