In a medium bowl, whisk together the 2 egg yolks, milk, and vanilla extract until smooth. Sift the cake flour and baking powder into the bowl and whisk gently until just combined. Do not overmix.

In a large, clean bowl with an electric mixer, beat the 2 egg whites and cream of tartar on medium speed until foamy. Slowly add the granulated sugar while beating. Increase speed to high and beat until stiff, glossy peaks form.

Gently fold about 1/3 of the meringue into the egg yolk batter to lighten it. Add the remaining meringue and fold carefully with a spatula until just a few streaks of white remain.

Set a large, lidded non-stick skillet over the lowest possible heat. Lightly grease the pan and the inside of four 3-inch ring molds. Place the molds in the warm skillet.

Divide the batter evenly among the molds, filling them about 3/4 full. Add 1 tablespoon of water to an empty part of the pan (to create steam) and immediately cover with the lid.

Cook for 9-12 minutes, or until the pancakes have risen to the top of the molds and the surface appears set.

Carefully flip the pancakes. Add another tablespoon of water to the pan and cover again. Cook for another 4-6 minutes, or until golden brown and cooked through.

Remove from the pan, carefully take off the molds, and serve immediately with your favorite toppings.