Preheat oven to 350°F, 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 ¼ 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. Let cool 20 minutes before unmolding onto a rack. Let cool completely before filling and icing.