How to reheat the colored cake?

Colorful cakes can be reheated directly in the steamer. Vietnamese banlan cake is a delicious food. Ingredients: 4 portions of mung bean kernels, glutinous rice flour 1 cup, half a cup of sweet potato flour, half a cup of fine sugar, 5 cups of coconut milk, and isatis indigotica essence 1 teaspoon. After heating, it can be directly steamed in a steamer, and the steamed gorgeous cake tastes better.