Cats' Tongues

A langue de chat batter, transcribed with its weights and volumes side by side. The weights are the ones to trust; at least one of the cup equivalents does not agree with them.

• Trust the ounces, not the cups6 oz of confectioners' sugar is closer to 1 1/3–1 1/2 cups sifted, not the 3/4 cup printed here. Weigh: 8 oz butter, 6 oz sugar, 2 oz flour, plus 5 egg whites (about 5 1/2 oz).
• Stray line at the endThe closing "1 lb. (4 cups) flour, 1 teaspoonful salt" belongs to the next recipe in the book and has nothing to do with these cakes. Ignore it.
• A cool ovenPeriod sources put a 'cool' or 'slow' oven somewhere in the region of 250–325F; the book gives no number, only 'until a pale brown color.' Modern practice for langues de chat tends to run hotter and faster — around 375–400F for 6–9 minutes — on the principle of set edges and a still-pale centre; a long slow bake dries them into crackers.
• The batter is very richFour times as much butter as flour by weight means it will spread hard and thin. Space the heaps at least two inches apart and expect wide, lacy-edged wafers rather than neat fingers.
• Add the whites one at a time and no fasterThis is the hinge. Cold whites dumped in together will split the creamed butter and the batter will weep butter on the tray. Have the whites at room temperature and beat each one in fully before the next.
• Piping beats spooning"Small long heaps" are most easily made with a plain 1/2-inch tip, piped in 2 1/2-inch lengths. A buttered and floured tin works, but parchment is more reliable with a batter this rich.
• Lift them warmThey firm as they cool and will crack if you fight them cold. Slide them off within a minute of leaving the oven, and drape them over a rolling pin if you want the curved shape.
• YieldA large batch, several dozen small wafers. They stale by softening rather than hardening, so keep them airtight with a lid on the tin.