In a mixing bowl, whisk together the flour, cornstarch, baking powder, and salt. Set aside.

In another bowl, combine the milk, egg yolks, granulated sugar, and vanilla extract. Mix until smooth.

Gradually add the dry ingredients to the wet mixture, stirring until just combined. Do not overmix.

In a separate bowl, beat the egg whites with the cream of tartar until stiff peaks form.

Gently fold the beaten egg whites into the batter in three additions, being careful not to deflate the mixture.

Preheat a non-stick skillet over low heat and lightly grease it with butter or oil.

Use a ring mold or cookie cutter to pour about 1/4 cup of batter into the skillet. Cover with a lid and cook for about 4-5 minutes until the bottom is golden brown.

Carefully flip the pancake, cover again, and cook for another 4-5 minutes until cooked through. Repeat with the remaining batter.

Serve warm, dusted with powdered sugar and drizzled with maple syrup.