In a bowl, whisk together the egg yolks, milk, and vanilla until smooth.
Sift in the cake flour and baking powder, then mix until just combined.
In a separate bowl, whip the egg whites with cream of tartar until foamy.
Gradually add sugar and beat until stiff peaks form.
Gently fold the egg white mixture into the yolk mixture in three additions.
Preheat a nonstick pan over low heat and lightly grease with oil.
Scoop pancake batter into tall mounds in the pan.
Add a couple teaspoons of water to the pan and cover with a lid.
Cook for about 5-6 minutes, flip carefully, add more water, and steam another 4-5 minutes.
Serve immediately with butter, syrup, or powdered sugar.