Place 90g of black rice and 50g of glutinous rice into the food processor separately and grind them into fine powders.

Separate the egg whites and yolks of the 2 eggs into two clean, dry containers. Put the egg whites in the freezer for 15-20 minutes. Freezing the egg whites makes it easier to whip them.

Add 10g corn oil to 90g milk. Use a whisk or chopsticks to mix thoroughly until the oil and milk emulsify into a smooth mixture.

Add the two egg yolks into the milk and oil mixture, stirring well until fully incorporated and the color is uniform.

Sift the black rice flour and glutinous rice flour into the egg yolk mixture. Use a spatula to gently mix into a smooth batter. When mixing, fold from the bottom up to avoid overworking the batter, which would affect the soft texture of the cake.

Take the frozen egg whites out of the freezer and gradually add 30g white sugar (up to 40g for a sweeter taste), in three batches. Add about a third of the sugar in the first batch and mix on low speed with an electric mixer until large, coarse bubbles form.

Add the second batch of sugar and increase the speed to medium. Continue mixing until the foam becomes finer and the volume increases.

Add the final batch of sugar and increase the speed to high. Whip the egg whites until they form soft peaks—when you lift the whisk, the peak should stand up with a slight curve at the tip and not easily fall.

Take a third of the whipped egg whites and gently fold it into the black rice batter using a spatula, folding from the bottom up. Be gentle to avoid deflating the egg whites.

Once combined, pour the black rice batter back into the remaining egg whites. Continue to fold quickly and gently until the batter is uniform in color and there are no visible streaks of egg whites or batter separation.

Pour the mixed batter into the mold and gently tap the mold to release any air bubbles.

Cover the mold with plastic wrap and poke small holes in it with a toothpick.

Fill a steamer with water and bring to a boil. Once the water is boiling, place the mold into the steamer and cover the lid. Steam on medium heat for about 35 minutes. Avoid opening the steamer during cooking to ensure the cake rises properly.

Once steamed, remove the mold and let the cake cool slightly. When it's cool enough to handle, use a knife to gently run around the edges of the mold, then invert the cake onto a plate and carefully remove the mold.

Sprinkle dried osmanthus on top of the cake for decoration, adding a nice fragrance and enhancing the appearance.

Finally, cut the black rice cake into evenly-sized pieces, and it's ready to enjoy!