GATEAU (a la Dauphine)

A whisked sponge with no chemical leavening at all: every bit of lift comes from the air beaten into ten eggs. The technique, not the ingredient list, is what makes or breaks it.

• Fold, do not stirThe instruction to "stir them in" is of its period; treat it as folding. Cut the whipped whites through the yolk batter with a spatula in as few strokes as will just combine them, adding a third at a time. Beat them in properly and you will have a flat, leathery cake.
• "A good oven"The book gives no temperature; for a large egg sponge this is usually read today as a moderate oven, somewhere around 350F (175C). Much hotter risks setting the crust before the interior has risen, and the middle sinks.
• Pounded sugarLoaf sugar crushed in a mortar, i.e. caster sugar. Half a pound is about 1 cup plus 2 tablespoons; granulated will work but dissolves less readily into the yolks.
• Chopped lemon-rindA tablespoon of hand-chopped peel is coarse by modern standards. Use the finely grated zest of one large lemon, taking no white pith.
• Rose-waterStrengths vary widely, and some modern bottlings are far more concentrated than others. Two tablespoons of a strong modern extract may taste of soap; start with two teaspoons and judge by smell.
• Flour and weightsA quarter pound of flour is about 4 oz, roughly 1 cup minus a tablespoon when spooned and levelled. Sift it before folding in; "the best flour" of the period meant a fine white flour, though how it compared with modern all-purpose flour is not something the recipe tells us.
• The tinWell-oiled is not enough for a lean sponge with this much sugar. Butter an 8- or 9-inch round tin and line the base with parchment; a plain-sided tin lets the batter climb better than a non-stick one.
• Doneness and yieldForty minutes at 350F is about right for a 9-inch tin; the top should spring back and a skewer come out clean. Cool in the tin ten minutes, then on a rack. Serves eight to ten.
• The cost note1s. 2d. is the pre-decimal price the publishers reckoned for the ingredients in the 1870s-80s. It tells you eggs and sugar were the expense, and it has no modern equivalent worth calculating.