Missing Ingredient

Mom knew what to do. She found a peanut-butter cookie recipe with precisely 12 ingredients. She mixed and baked a dozen cookies, omitting one ingredient per cookie. Mom then arranged and labeled the cookies, each quite unique, in a display box.
I toted this science project to school. When the science-fair winners were announced, I took first place for the second grade! I treasured the blue ribbon and seeing my photo (“Future Scientist”) in the local newspaper.
For the third-grade science fair, Mom experimented with egg yolks. I won first place again! With a pinch of guilt, once more I sopped up the prestige reserved exclusively for the winner’s-circle crowd.