According to Wikipedia, Mochi is a Japanese rice cake pounded into paste and molded into shapes. In Japan it is traditionally made in a ceremony called mochitsuki. While also eaten year-round, mochi is a traditional food for the Japanese New Year and is commonly sold and eaten during that time. Mochi is also a prominent snack in Hawaii and several other Southeast Asia countries.
My mochi recipe from the blog Zakka Life does not call for pounding or molding, but the author does seem to know what she's doing. I made a half recipe since it called for a 29 oz can of pumpkin and I could just use a 15 oz one. I cooked it in a 9 x 9 pan. Mine looks a little dryer than hers, but it tasted great. I really like these sweet little cakes. Finding rice flour took a trip to the international market, but I love that place.