Prepare the lemon: Use a grater to gently zest the lemon, scraping only the yellow part of the skin. Be careful to avoid the white inner layer, which can be bitter. Set the lemon zest aside. Squeeze a small amount of lemon juice (about 3-5 drops) for later use to neutralize the egg smell.

Whisk the eggs: Crack the 5 room-temperature eggs into a large, clean bowl (make sure it's free of oil and water). Add the 3-5 drops of lemon juice or white vinegar to reduce the eggy smell. Next, add the 25g of condensed milk and 50g of white sugar. Start by whisking on low speed until the sugar and condensed milk dissolve, and the egg mixture lightens in color (about 1-2 minutes). Then, increase the speed to medium and continue whipping until the egg mixture forms a trail in the shape of an "8" on the surface when you lift the whisk, and the "8" shape should remain visible for a long time without fading.

Mix the dry ingredients and batter: Sift 150g low-gluten flour and 5g baking powder together, then sift the mixture into the whipped eggs. Gently fold with a spatula from the bottom up until well combined. Be careful not to stir in circles to avoid deflating the batter. Continue folding until there are no visible dry flour spots, and the batter is smooth and slightly thick.

Add lemon zest and corn oil: Add the lemon zest you prepared earlier into the batter. Then, pour in the 30g of corn oil and gently fold it all together with a spatula. The batter should now be smooth, with a fresh lemon fragrance.

Prepare the mold and fill with batter: Line your steamable cake mold with parchment paper (skip this step if using silicone molds). Evenly distribute the dried fruit at the bottom of the mold (you can skip this step if you prefer a plain cake). Transfer the batter into a piping bag, cut a small hole at the tip, and pipe the batter into the mold, filling it about 70-80% full. The cake will expand during steaming.

Remove air bubbles: Gently tap the filled mold on the counter to release any large air bubbles. This will help ensure a smooth, even texture and avoid air pockets in the cake.

Steam the cake: Add enough water to your steamer, bring it to a boil over high heat, and then place the mold into the steamer. Cover with a lid, turn the heat to medium, and steam for 15 minutes. Avoid opening the lid while steaming, as this can cause the steam to escape and affect the cake's rise.

Remove the cake from the mold: After 15 minutes, check the cake. If it's done, remove the mold from the steamer (using heat-resistant gloves). Place the mold on a cooling rack to cool slightly. Once it's cool enough to handle, gently remove the cake from the mold, and it's ready to serve.