Jaconde Sponge

Jaconde is the thin almond-based sponge cake used in classic French patisserie for opera cakes and any rolled or vertically constructed dessert. Unlike a standard genoise, Jaconde uses ground almonds in place of some flour, giving it a delicate nuttiness and a flexible, tender crumb that bends without cracking. Bakers spread it in a sheet pan, bake briefly at moderate heat, and turn it out warm so it stays pliable for rolling. The almond content also keeps it from drying out the way a flour-only sheet sponge tends to. If you can find blanched almond flour, Jaconde is well within home reach.