Emulsify the liquids: In a large bowl, add the milk and corn oil. Whisk until fully emulsified — smooth and glossy with no visible oil separation.

Add the dry ingredients: Sift in the cake flour. Mix gently using a folding or “Z” motion until the batter is smooth and lump-free. Avoid circular stirring, which can activate gluten and make the cake tough.

Incorporate the egg yolks: Separate the egg yolks from the egg whites. Add the yolks one by one, folding until fully combined. The batter should be smooth and flow easily.

Prepare the egg whites: Place the egg whites in a completely clean, dry bowl with no traces of oil or water. Add a few drops of lemon juice and start beating on medium-high speed.

Add sugar in two stages: When large bubbles form, add half the sugar. Continue beating until fine bubbles appear, then add the remaining sugar. Beat until glossy and stiff peaks form — the tips should stand upright.

Stabilize with cornstarch: Once stiff peaks are achieved, add the cornstarch and beat on low speed for about 10 seconds to combine evenly.

Fold together: Add one-third of the meringue to the yolk batter. Gently fold using a spatula, scooping from the bottom to the top. Pour this mixture back into the remaining meringue and continue folding until just combined. The batter should be smooth and uniform, with no visible white streaks.

Preheat the rice cooker: Lightly brush the inner pot with oil. Turn on any cooking function (such as “Cook Rice”) and preheat for about 5 minutes, then switch it off.

Pour the batter: Pour the batter into the preheated pot. Tap the pot gently 2–3 times to remove large air bubbles. If using cranberries, sprinkle them evenly on top.

Cook: Select the “Cake” function if available, or use “Porridge” or “Cook Rice” mode. Cook for about 50 minutes.

Rest: Once the cycle ends, do not open the lid immediately. Let the cake sit covered for 3 minutes to stabilize.

After resting, remove the inner pot and invert the cake onto a wire rack immediately. Gently lift off the inner pot, and the cake will release easily. Your fluffy rice cooker cake is ready!