Place 80g of white granulated sugar into a bowl. Add 240g of hot water and stir until the sugar is completely dissolved.

In a large mixing bowl, combine 360g of rice flour and 145g of glutinous rice flour. Mix thoroughly.

Slowly pour the dissolved sugar water into the flour mixture, stirring continuously until a coarse, grainy texture forms.

Put on gloves to gently break apart any larger clumps in the mixture.

Sift the flour mixture to remove any remaining lumps and divide it into three portions, about 270g each.

Take one portion (270g) of the flour mixture and add 50g of black sesame powder along with 1 tbsp of white granulated sugar. Adjust the sugar according to your preference and mix until evenly combined.

Line a suitable container with steaming cloth or gauze. Place a mousse ring in the container to create a mold (if unavailable, use a breathable steaming tray).

Start by adding one portion of the plain flour mixture as the base layer. Use a spatula to gently spread it out evenly without pressing, as pressing will make the cake less fluffy.

Next, add the black sesame flour mixture layer and spread it out gently with the spatula.

Finish by adding the remaining plain flour mixture on top, again spreading it lightly to create a smooth layer.

Use a spatula to lightly score the surface into small squares for easy cutting later.

Sprinkle the surface evenly with dried osmanthus flowers.

Cover the container with gauze to prevent condensation from dripping onto the cake.

Place the container in a steamer over cold water. Bring the water to a boil, then reduce to medium heat and steam for about 40 minutes, adjusting the time as needed based on the thickness of the cake.

Carefully remove the container from the steamer and allow the cake to cool slightly.

Once cooled, gently unmold the cake. If desired, drizzle osmanthus syrup over the surface for an added layer of osmanthus aroma.