Preheat oven to 177°, slide rack onto the lower-middle level, and prepare your pan (see Note). Sift the flour with the 1 tablespoon sugar and salt and reserve the clarified butter in a 2-quart bowl. Beat the eggs in your mixer bowl with the remaining sugar and the vanilla until you have formed the ribbon. At once, rapidly sift on and fold in a quarter of the flour, then half the rest of the flour, and finally the last of it. Fold a large plop of this cake batter into the clarified butter, then fold the butter-batter back into the remaining batter. Turn batter into prepared pan, filling it to no more than inch of the rim. Bang lightly on work surface to deflate bubbles, and bake 30 to 35 minutes, until puffed, lightly browned, and showing a faint line of shrinkage from sides of pan.