Lady Fingers

A four-ingredient sponge that lives or dies on how you fold the whites. Everything else is a matter of translating weights and an oven description.

• The weightsOne-quarter pound of flour is about 1 cup of all-purpose. One-quarter pound of sugar is about 1 cup if it is sifted confectioners', but closer to half a cup by volume if it is finely ground granulated, which is why weighing is better here than measuring; the batter has no leavening beyond the egg whites.
• Fold, do not stirThe hinge of the recipe. The whites are the only lift; sift the flour over the yolk-sugar base and cut the whites in with a spatula in a few decisive strokes. Overworked batter spreads into flat wafers instead of holding a raised finger shape.
• "Powdered sugar" in 1900"Powdered sugar" in older books -- In older American books this often means finely ground granulated sugar rather than today's cornstarch-cut confectioners' sugar. Superfine (caster) sugar is the closer match and dissolves into the yolks more readily.
• Bake quicklyThe recipe gives no oven description beyond 'quickly'; a hot oven in the region of 400 to 425F suits these, and at that heat ladyfingers take roughly 6 to 9 minutes -- pale gold at the edges, dry to the touch, still soft within. Left longer they turn into hard biscuits.
• Buttered paperParchment is easier to work with than buttered paper. A piping bag with a plain half-inch tip gives even fingers; the recipe leaves the shape and size to the cook. Two spoons will work but the results are less uniform.
• Pressing while hotThe pairing only works in the first minute or two out of the oven, while the flat undersides are still tacky. Once cooled they will not adhere without a filling.
• YieldAbout 24 to 30 single fingers, or a dozen to fifteen joined pairs.
• StorageThey stale fast and go soft in humidity. Keep them airtight, or dry them out in a low oven if you want them firm enough to line a charlotte mould.