- 5 eggs, separated, at room temperature
- 3⁄4 cup sugar
- 1 tsp. vanilla extract
- 1⁄4 tsp. fine sea salt
- 1 cup cake flour
In a bowl, whisk together the egg yolks and 1⁄2 cup of the sugar until the mixture is pale and the batter is thick enough to leave a slowly dissolving ribbon on the surface when dropped from the whisk, about 4 minutes. Beat in the vanilla.
In a large bowl, using a balloon whisk, beat the egg whites until foamy. Add the salt and beat until soft peaks form. Beat in the remaining 1/4 cup sugar a little at a time until stiff, glossy peaks form. Stir a large spoonful of the whites into the yolk mixture to lighten it. Sift one-third of the flour over the batter and gently fold it in until blended. Fold in half of the remaining whites. Sift another third of the flour over the batter and fold in. Repeat with the remaining whites and flour, ending with the flour.
Pour the batter into the prepared pan and smooth the top. Bake until the cake is golden brown and puffed, 35 to 40 minutes. Transfer the pan to a wire rack and let the cake cool for 10 minutes. Remove the sides of the pan. Invert the cake onto the rack and remove the pan bottom and the paper. Turn the cake right side up and let cool completely.