In a medium mixing bowl, whisk egg yolks and 1 tablespoon of sugar until pale and frothy. Whisk in whole milk and vanilla extract.

Sift in the cake flour, baking powder, and pinch of salt. Whisk gently until a smooth, lump-free custard base forms. Set aside.

In a clean, grease-free glass or metal bowl, beat chilled egg whites on medium-low speed until foamy. Add cream of tartar.

Gradually sprinkle in 2 tablespoons of sugar, one-third at a time, increasing mixer speed to medium-high. Beat until glossy, stiff peaks form that stand straight up when the beaters are lifted (about 4–5 minutes). Do not over-beat until dry.

Scoop one-third of the whipped meringue into the egg yolk bowl. Whisk vigorously to lighten the dense batter.

Gently transfer the remaining meringue into the bowl. Using a silicone spatula, fold with wide circular motions from bottom to top, rotating the bowl, until just incorporated with no visible white streaks. Handle with extreme gentleness to preserve the trapped micro-bubbles.

Heat a heavy non-stick skillet or griddle over the LOWEST possible heat setting for 3 minutes. Lightly grease with butter, wiping off excess with a paper towel.

Using an ice cream scoop, drop 3 tall mounds of batter onto the pan. Add 1 teaspoon of water into the empty spaces of the pan. Cover immediately with a tight domed lid and steam for 3 minutes.

Uncover, dollop a second scoop of batter directly on top of each pancake to create sky-high height. Add another teaspoon of water, cover, and steam for 4 more minutes until the sides feel slightly set.

Very gently flip each pancake with a thin flexible spatula. Add 1 teaspoon of water, cover, and steam the second side for 4–5 minutes until golden brown and cooked through. Transfer immediately to warm plates. Dust with powdered sugar, top with melting butter, maple syrup, and fresh berries.