Separate the egg whites and yolks into two different bowls. Place the whites in the freezer for 15 minutes to chill.
In the bowl with yolks, whisk in the milk and vanilla extract until frothy.
Sift the cake flour and baking powder into the yolk mixture and whisk until smooth and combined. Set aside.
Remove egg whites from freezer. Add cream of tartar. Using a hand mixer, beat on medium speed until frothy.
Gradually add the sugar to the egg whites one-third at a time while beating. Continue whipping until stiff, glossy peaks form (the meringue should stand up straight when the beater is lifted).
Gently fold one-third of the meringue into the yolk batter with a spatula to lighten it.
Add the remaining meringue and fold very gently to incorporate without breaking the air bubbles. Stop as soon as no white streaks remain.
Heat a non-stick frying pan over very low heat. Lightly grease with vegetable oil and wipe off excess with a paper towel.
Scoop the batter into the pan, stacking 2-3 scoops on top of each other to create tall, thick mounds.
Add 1 tablespoon of water to empty spaces in the pan (not touching the batter) and immediately cover with a lid.
Cook for 4-5 minutes on low heat. The batter should rise and the bottom should be golden brown.
Carefully flip the pancakes. Add another teaspoon of water if dry, cover, and cook for another 4-5 minutes.
Transfer to a plate immediately and serve with toppings. Serve instantly as they will deflate quickly.