The skin of the red tortoise cake is made from glutinous rice flour dough, mashed sweet potato, water, food coloring, sugar, oil and wheat starch. Traditionally, fillings for red tortoise cakes are made with mung bean paste or grounded peanuts, sugar and oil. The fillings are placed within the dough and the tortoise shell design imprinted on the skin's surface using molds before the red tortoise cakes are steamed over a piece of banana leaf.