Mix the Liquid Ingredients: In a large bowl, combine 140g of milk, 30g of white sugar, 1 egg, 3g of yeast, and 3g of salt. Use chopsticks or a whisk to mix until the sugar and yeast dissolve completely and the ingredients are well combined.

Add the Flour: Gradually add 250g of flour into the liquid mixture. Use a scraper to stir until the flour is fully incorporated, forming a slightly rough dough. The dough might be a bit sticky at this point, which is normal.

Add Butter and Combine: Add 20g of softened butter into the dough (or vegetable oil if using). Continue mixing with a scraper until the butter (or oil) is fully absorbed and the dough becomes smooth and shiny.

Chill for Hydration: Cover the dough with plastic wrap and refrigerate for 20 minutes. Hydrating the dough helps the flour absorb moisture, making the dough easier to handle later and improving the bread's texture.

Knead the Dough: After refrigerating, remove the dough from the fridge. The dough will be firmer. Gently pull and press the dough repeatedly until it becomes smooth. Be careful not to tear the gluten, as this will affect the bread's texture.

First Fermentation: Cover the kneaded dough with plastic wrap and place it in a warm spot, such as a warm room or an oven with a fermentation setting (ideally at 30-35°C). Let it ferment until the dough has doubled in size.

Punch Down and Divide: After fermentation, the dough will be filled with air bubbles. Transfer it to a flat surface and gently press down to release the air. Then, use a knife or scraper to divide the dough into 8 equal portions.

Shape into Balls: Take one portion of dough and fold it in from the outside to the center, shaping it into a ball. Use your palms to roll the dough, making the surface smooth and firm. Repeat with the remaining portions.

Prepare and Place in Air Fryer: Line the air fryer basket with parchment paper to prevent sticking. Place the shaped dough balls in the air fryer, leaving enough space between them as they will expand during the second fermentation and baking.

Second Fermentation and Decoration: Let the dough balls rest in a warm place for 25 minutes to allow them to rise. Once risen, brush the surface of each ball with egg yolk and sprinkle with sesame seeds for decoration.

Baking: Set the air fryer to 140°C and bake for 20 minutes. After 20 minutes, carefully flip the bread using chopsticks or tongs and bake for another 10 minutes at 140°C. Keep an eye on the bread's color through the air fryer's glass—when the surface turns golden brown and the aroma fills the air, the bread is done.