Preheat your oven to 160°C (top and bottom heat). Line a 28×28 cm baking pan with parchment paper to prevent sticking and for easy removal after baking.

Wash and finely chop the green onions, set them aside for later use.

In a large, clean bowl, carefully separate the egg whites and yolks from 5 eggs, placing them into two separate bowls.

Pour 60g of milk and 50g of corn oil into a new bowl. Using a hand whisk or chopsticks, stir in a “Z” shape to emulsify the mixture. Keep mixing until the liquid is smooth and uniform, with no visible oil droplets, and the texture becomes silky and smooth.

Sift in the dry ingredients (either 50g of all-purpose flour or 40g of high-gluten flour combined with 10g of cornstarch) into the emulsified mixture. Then, gently fold the flour into the liquid using a spatula, stirring from the bottom up until fully combined.

Next, add the egg yolks along with 1g of salt to the mixture. Stir until the batter is smooth and has a yogurt-like consistency. If the batter is too thin, add a little more flour; if it's too thick, add a small amount of milk, adjusting gradually and stirring constantly to avoid making the batter too runny or too stiff.

In a clean bowl for egg whites, add a small amount of white vinegar. Add 50g white sugar and use an electric mixer to whisk the egg whites on high speed until soft peaks form. The egg whites should be glossy and form a small curved peak when the whisk is lifted.

Gently fold one-third of the whipped egg whites into the batter. Use a spatula and quickly and gently fold from the bottom up, being careful not to deflate the egg whites. Once incorporated, pour the batter back into the remaining egg whites and continue to fold gently until the mixture is smooth and fluffy.

Pour the batter into the prepared baking pan from about 28 cm above the surface to allow the batter to settle evenly. Gently tap the pan's edges to release any air bubbles.

Sprinkle the chopped green onions, sesame seeds, and pork floss evenly over the surface. Adjust the amount of pork floss to your taste.

Place the pan in the preheated oven and bake for 20 minutes at 160°C. After 20 minutes, reduce the temperature to 140°C and continue baking for an additional 20 minutes. Avoid opening the oven door frequently during the baking process.

Once baked, remove the cake from the oven and place it on a cooling rack. Immediately peel off the four corners of the parchment paper to allow the steam to escape. Let it cool to room temperature.

Once cooled, cover the top with parchment paper and flip the cake over. Carefully peel off the top parchment paper. Use a knife to cut one side of the cake at a 45-degree angle to remove any excess cake.

Start by rolling the cake once to form a small coil. Then, press the rolling pin against the parchment paper with one hand while using the other hand to pull the parchment forward, rolling the cake tightly and evenly.

Let the pork floss roll set for 30 minutes. For faster setting, you can place it in the fridge to help it firm up and hold its shape. Once set, cut into your desired portion sizes.