In a large mixing bowl, combine the hot water and brown sugar. Stir with chopsticks until the sugar is completely dissolved. Allow the mixture to cool until it is just warm to the touch (about 35°C / 95°F). Test it on your wrist—it should feel comfortable, not hot. Whisk in the egg until fully incorporated. Finally, sprinkle in the yeast and stir for about 30 seconds until it begins to dissolve. Set aside for 5 minutes.

Add the all-purpose flour to the liquid mixture. Using chopsticks, stir in one direction until you have a perfectly smooth, lump-free batter. This should take just a minute or two—stop once it's combined; overmixing is unnecessary. Cover the bowl tightly with plastic wrap or a damp cloth. Place it in a warm, draft-free spot and let it rise for 40-50 minutes, or until the batter has doubled in size and is filled with bubbles.

Gently stir the chopped red dates into the risen batter with your chopsticks. This will fold them in and deflate the batter slightly, which is normal. Prepare your steaming molds (ramekins, small bowls, or a dedicated steaming tin) by brushing the interior lightly but thoroughly with cooking oil. Divide the batter among the molds, filling each only ⅔ to ¾ full to leave room for expansion. Cover loosely and let rise a second time in a warm place for 15-20 minutes, until the batter rises to just below the rim of the mold.

While the batter is on its second rise, bring water in your steamer to a full boil. Once the batter has risen, garnish the top of each cupcake with a reserved red date half and a sprinkle of black sesame seeds. Carefully place the molds into the steamer, leaving a little space between them. Cover the steamer with a lid.

Steam over medium-high heat for 20 minutes. It's crucial not to peek during this time! After 20 minutes, turn off the heat. Do not open the lid.Let the cupcakes sit in the steamer, covered, for an additional 3minutes. This resting period prevents them from collapsing due to a sudden change in temperature and steam.

Carefully remove the molds from the steamer. Let them cool on a rack for 5-10 minutes until they are cool enough to handle. Silicone molds can be gently pulled away to release the cake, while regular bowls can be loosened by running a knife around the edge before inverting.