Heat a large nonstick skillet over medium-low heat while you prepare the batter. Use 2 pans if you have them so you can cook all the pancakes at once, which is ideal.

Place 4 cold large egg whites and ¾ teaspoon cream of tartar in a stand mixer with the whisk attachment. Turn the mixer on to medium-low speed (setting 4 on a KitchenAid mixer) and slowly stream in 2 tablespoons of the granulated sugar, about 1 minute. Continue to beat until very foamy and growing in volume, about 2 minutes more. Increase the speed to medium (setting 6) and beat until opaque and just about soft peaks, 2 to 3 minutes. Increase the speed to medium-high (setting 8) and beat until doubled in volume, glossy, holds a stiff peak, and the bowl can be turned over without the meringue moving, 1 to 2 minutes.

Whisk 2 cold large egg yolks, 2 tablespoons whole milk, and 1 tablespoon vanilla extract together in a large bowl. Whisk in the remaining 2 tablespoons granulated sugar and ¼ teaspoon kosher salt.

Sift ⅓ cup all-purpose flour, 1 tablespoon cornstarch, and 1 teaspoon baking powder over the egg yolk mixture and whisk until just combined and no dry bits remain.

Fold ⅓ of the egg white mixture into the yolk mixture with a flexible spatula until just combined and the yolk mixture is airy. Some streaks remaining of each mixture are OK. Add the remaining egg white mixture and fold until just fully combined.

Brush or wipe a layer of melted butter over the skillet. It should not pool.

Using a 2- to 3-tablespoon scoop, scoop 3 portions of batter onto the skillet, spacing them evenly apart. Repeat scooping 2 more scoops of batter onto each pancake, piling the scoops up and using the bottom of the scoop to slightly flatten each one so the pancakes maintain a consistent shape.

Drizzle 1 teaspoon water around the skillet (don’t worry if it runs into the pancakes) and cover with a tight-fitting lid. Cook until the tops are set and don’t stick to your finger when gently pressed, the pancakes easily release, and the bottoms look light golden to golden-brown when the edge is gently lifted with a thin spatula, 8 to 10 minutes (reduce the heat if you notice browning around the edges of the pancakes too early). Meanwhile, refrigerate the remaining batter.

Top each pancake off with another scoop of batter, keeping it in the center so it doesn’t spill over and flattening it slightly to sit evenly on top. Refrigerate any remaining batter. Cover and cook until the top is set, 2 to 3 minutes.

Using a flat spatula, gently flip each pancake over. Drizzle 1 teaspoon water around the pancakes. Cover and cook until the second side is light golden-brown and set, 5 to 7 minutes more.

Serve immediately, dusting with powdered sugar and topping with butter and maple syrup as desired. Repeat greasing the pan and cooking the remaining batter. The second batch might not rise as high.