A patent filing for the process explains how this happens. In chocolate production, there is a process called conching in which a container filled with metal beads grinds all the ingredients (cocoa butter, milk, sugar, oils, etc.) together. During this step, Cadbury has figured out a way to shear sugar particles into much smaller pieces than before, and somewhat counterintuitively (because one would think that this would create more surface area on a given volume of sugar) less fat ends up coating those sugar particles. This is because these smaller particles don't get completely coated in fat, and parts of their surface areas remain exposed. "Such exposed sugar particle faces contribute towards a more sugar continuous system (sugar matrix)," the patent filing reads, "reducing the percentage of fat coated sugar particles which is believed to be advantageous for temperature tolerant properties."