Little Cookie makes his way around the Museum of Modern Cookie, stealing priceless pieces of cookie art. He leaves behind traces of crumbs, butter and chocolate chips, which help Elmo, Chris and Cookie Monster figure out who the thief is. They eventually corner him in his lair (within the walls of the museum), where the cookie art is all kept.
He claims he loves cookie art so much, he just can't control himself. The gang teaches him that art is for everyone to enjoy and he can focus his energy better by making his own art. Following an accident with art supplier Grover, he creates his own piece of cookie art - a colorful, splatter impression of himself, which he titles, The Cookie. The piece finds its way into the museum afterward.