Make the water dough. Mix flour, water, and lard and knead the mixture into a smooth dough.

Make the oil dough. Mix flour and lard and knead to form a dough.

Divide both water and oil dough into 13 portions each. Cover the dough balls with plastic wrap and let them rest for 10 minutes. The water dough balls should be larger than the oil dough balls.

After letting it rest, flatten a water dough ball into a circular wrapper and place the oil dough ball in the center. Seal it by pinching the edges and shaping the dough into a new ball.

Flatten the combined water and oil dough ball into a flat oblong sheet. Then, roll it up from one end to form a rolled sheet. Repeat these steps for the rest of the dough balls. After combining and rolling all the dough pieces, let them rest for another 10 minutes while covered in plastic wrap.

After resting, take a piece of rolled dough, flatten it again into a long oblong sheet, and roll it up. Then, press the middle part with your thumb, and fold both sides to the center.

Flatten the dough into a circular wrapper. Prepare the sweet bean paste. Make about 13 balls of the paste. Place the sweet bean paste in the center of the dough wrapper and seal the edges by pinching.

Place the cakes on a baking tray lined with parchment paper, gently press the balls to flatten them to about 1 cm thick, and brush with egg yolk on top.

Use a sharp knife to make 3 cutouts on the top of each wife cake and sprinkle with white sesame seeds.

Preheat the oven to 350°F and bake for 20 minutes. After baking, do not open the oven door immediately or this may cause the cakes to deflate. If the cakes didn't puff up during baking, you may need to increase the time or temperature since the oven temperature and the cake size can affect the results. After storing the cakes in the fridge, you can reheat them in the oven at 350°F for 10 minutes or more.