1. Cover the steamer with greased paper. I don't have a bamboo steamer, and I used an 8-inch drain pot. It is best to use air-permeable containers for steamed mara cakes.
2. Add brown sugar to whole egg and thicken.
3. Slowly pour the milk or three-flower evaporated milk and mix well.
4. Sift in all powders.
5. Stir until there are no particles.
6. Put oil and vanilla extract in a bowl, add 2 tablespoons of batter and mix well.
7. Pour back into the batter and mix well.
8. Pour into the bamboo steamer covered with oil paper. (The 6-inch can be two, I used an 8-inch skimmer.)
9. Cover with a lid or plastic wrap and let it stand for 30 minutes.
10. Bring the water in the steamer to a boil, put the batter in, and steam on high heat for 25 minutes.
11. Take it out immediately after steaming.
12. It's soft when eaten hot or cold.
