In honor of National Peanut Butter Cookie Day, we are taking a look at the history behind this beloved treat. It was invented in the 1910s when George Washington Carver of Alabama's Tuskegee Institute published a peanut-themed cookbook to help promote the crop. The cookbook was called, How to Grow the Peanut and 105 Ways of Preparing It for Human Consumption. In it, Carver included several cookie recipes that used chopped peanuts. Approximately 20 years later, peanut butter was added to the cookies instead of the chopped peanuts. Additionally, the characteristic fork marks were added at this time. Today, the peanut butter cookie remains a beloved classic that’s often seen at holiday parties.