Creating fluffy and jiggly Japanese souffle pancakes is a fun process that can be done easily by following these steps:

1. Prepare the Batter: In a large bowl, separate the egg whites and yolks. Add the sugar to the egg yolks and whisk until the mixture becomes creamy and pale in color.
2. Add Milk and Vanilla: Stir in the milk and vanilla extract into the egg yolk mixture until well combined.
3. Incorporate Dry Ingredients: Sift in the all-purpose flour, baking powder, and salt. Mix gently until just combined. Avoid overmixing.
4. Whip Egg Whites: In a separate bowl, use an electric mixer to beat the egg whites until they form soft peaks. Gradually add the remaining sugar and continue to beat until stiff peaks form.
5. Fold Mixtures: Gently fold the whipped egg whites into the batter in three additions, being careful not to deflate the airy mixture.
6. Preheat Pan: Heat a non-stick skillet over low to medium heat. Lightly grease it with cooking spray or butter.
7. Cook the Pancakes: Use a mold (round metal ring or cookie cutter) in the skillet to help maintain the shape. Spoon the batter into the mold about halfway full. Cover the pan with a lid and cook for 3-4 minutes until bubbles form on the surface.
8. Flip and Finish Cooking: Carefully flip the pancakes using a spatula. Cover again and cook for another 3-5 minutes until the pancakes are cooked through and have risen beautifully.
9. Remove and Serve: Lift the pancakes out of the mold and place them on a serving plate. Repeat until all batter is cooked.
10. Garnish: Dust with powdered sugar and add toppings as desired.

Following these steps will ensure your pancakes turn out fluffy, jiggly, and downright delectable!