In a medium bowl, whisk the egg yolks and 1 tablespoon of the sugar until pale. Stir in the milk and vanilla extract. In a separate large bowl, sift together the cake flour and baking powder. Pour the yolk mixture into the flour mixture and whisk gently until just combined. Do not overmix.

In a large, clean, dry bowl, beat the egg whites and cream of tartar with an electric mixer on medium speed until frothy. Gradually add the remaining sugar and increase the speed to high. Beat until soft peaks form—the peaks should hold their shape but curl slightly at the tip.

Gently fold about one-third of the meringue into the yolk mixture to lighten it. Add the rest of the meringue and continue to fold gently with a spatula until no white streaks remain, being careful not to deflate the batter.

Heat a large non-stick skillet over the lowest possible heat. Lightly grease the pan and the inside of your ring molds. Place the molds onto the skillet and fill each about 3/4 full with batter. Add 1 teaspoon of water to an empty part of the pan to create steam.

Cover the skillet with a lid and cook for 9-12 minutes, or until the top is set and bubbles have appeared. Carefully remove the lid, slide a spatula under each pancake, and gently flip. Cover again and cook for another 5-6 minutes until golden and cooked through.

Carefully remove the pancakes from the molds and serve immediately with your favorite toppings.