In a medium bowl, whisk together the egg yolks, milk, and vanilla extract. Gradually sift in the cake flour, baking powder, and salt. Mix until no lumps remain.

In a separate bowl, beat the egg whites until frothy. Gradually add the sugar and continue to beat until stiff peaks form.

Gently fold one-third of the egg whites into the yolk mixture, then incorporate the remaining egg whites.

Preheat a non-stick skillet over low heat and add butter. Using a cookie scoop, place mounds of batter onto the skillet. Pour water into the skillet and cover.

After 2 minutes, add another scoop of batter on top of each pancake. Cover and cook for another 5-6 minutes.

Gently flip each pancake, add more water, and steam for an additional 4 minutes.

Stack pancakes on a plate and serve immediately with your favorite toppings.