Pellegrino Artusi's bread from Spain

Reported as published (photo separately ...)

599. BREAD OF SPAIN 

• Eggs, n. 6.
• Fine powdered sugar, grams 170.
• Hungarian or very fine flour, grams 170.
• Smell of lemon peel to those who like it.

 Wring the egg yolks with the sugar first, then add the flour, dried on the fire or in the sun, and after processing for about half an hour pour two spoonfuls of the six whipped whites to soften the mixture, then stir the rest slowly.

You could also mount the eggs on the fire as in the Dolce alla Neapolitan n. 586. Bake it in the oven.