Pu 'er tea. The big round cake is a kind of Pu 'er tea, which looks like a round cake. It's a little round like a tea cake, but it's Pu 'er tea, not tea. Tea cake, or group tea, is a small tea cake produced in Song Dynasty. This is the first time that Ding Wei made it when he was an official in Fujian in the Song Dynasty, and it was for the palace to drink. The production process has experienced the historical evolution of adding spices first and then adding spices.