Indeed, cjc sounds like someone who has already tried this at home, right? What circumstances are different between ice cube trays and ice cream mixture? High surface area comes to mind. In the article the experiments described all involve volumes of water (or ice cream goo) that are in containers with low surface area to volume. SA and Volume do not scale linearly, thus the heat exchange rate would be faster for the ice cube trays. Of course, TRYING it out would not hurt. Several hundred years worth of scientists seem to have laughed at previous experimental results out of some egotistical belief that experimental results passed down from history are fairy tales.